Merge pull request #229 from tommilligan/prep-1.20.0

chore: prep v1.20.0 release
2025-12-27 13:30:47 -05:00 · 2025-06-06 14:53:02 +01:00 · 2025-06-06 14:35:51 +01:00 · 2025-06-06 14:21:49 +01:00 · 2025-06-06 12:58:11 +01:00 · 2025-06-06 12:37:47 +01:00
37 changed files with 3557 additions and 1109 deletions
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -6,12 +6,12 @@ jobs:
  # Fast test before we kick off all the other jobs
  fast-test:
    name: Fast test
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
    steps:
      - name: Checkout sources
        uses: actions/checkout@v4
      - name: Cache build files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
@@ -19,10 +19,9 @@ jobs:
            target
          key: fast-test-${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
-          override: true
      - name: Install more toolchain
        run: rustup component add rustfmt clippy
      - name: Run tests
@@ -32,34 +31,36 @@ jobs:
  detailed-test:
    needs: fast-test
    name: Test main target
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
    steps:
      - name: Checkout sources
        uses: actions/checkout@v4
      - name: Cache build files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
            ~/.cargo/bin
-            cargo_target
+            /tmp/cargo-install-target-dir
          key: detailed-test-${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
-          override: true
+          components: rustfmt, clippy
+      - name: Enable Corepack
+        run: corepack enable
      - name: Install node toolchain
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "yarn"
          cache-dependency-path: compile_assets/yarn.lock
      - name: Install additional test dependencies
        env:
-          CARGO_TARGET_DIR: cargo_target
+          CARGO_TARGET_DIR: "/tmp/cargo-install-target-dir"
        run: ./scripts/install
      - name: Run check script
        run: ./scripts/check
@@ -71,16 +72,16 @@ jobs:
    strategy:
      matrix:
        os:
-          - ubuntu-20.04
+          - ubuntu-24.04
        rust:
          - stable
          - beta
-          - 1.66.0
+          - 1.82.0
        experimental:
          - false
        include:
          # Run a canary test on nightly that's allowed to fail
-          - os: ubuntu-20.04
+          - os: ubuntu-24.04
            rust: nightly
            experimental: true
          # Test only stable on Windows, presume we'd get same result on other
@@ -90,7 +91,7 @@ jobs:
            experimental: false
        exclude:
          # Don't bother retesting stable linux, we did it in the comprehensive test
-          - os: ubuntu-20.04
+          - os: ubuntu-24.04
            rust: stable
            experimental: false
    runs-on: ${{ matrix.os }}
@@ -105,7 +106,7 @@ jobs:
      - name: Checkout sources
        uses: actions/checkout@v4
      - name: Cache build files
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
@@ -113,9 +114,8 @@ jobs:
            target
          key: test-${{ matrix.os }}-${{ matrix.rust }}-cargo-${{ hashFiles('**/Cargo.toml') }}
      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: ${{ matrix.rust }}
-          override: true
      - name: Run tests
        run: cargo test
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -25,7 +25,7 @@ jobs:
            # binaries, so we use the same glibc version
            #
            # ref: https://github.com/rust-lang/mdBook/pull/1955
-            os: ubuntu-20.04
+            os: ubuntu-24.04
            name: x86_64-unknown-linux-gnu.tar.gz
          - target: x86_64-unknown-linux-musl
            os: ubuntu-latest
@@ -43,19 +43,19 @@ jobs:

      # Cache files between builds
      - name: Setup | Cache Cargo
-        uses: actions/cache@v3
+        uses: actions/cache@v4
        with:
+          # Note that we don't cache the `target` directory here
+          # so we do a completely clean rebuild for artefacts
          path: |
            ~/.cargo/registry
            ~/.cargo/git
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}

      - name: Setup | Rust
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
-          override: true
-          profile: minimal
          target: ${{ matrix.target }}

      - name: Setup | cross
@@ -74,7 +74,7 @@ jobs:

      - name: Post Setup | Extract tag name
        shell: bash
-        run: echo "##[set-output name=tag;]$(echo ${GITHUB_REF#refs/tags/})"
+        run: echo "tag=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
        id: extract_tag

      - name: Post Setup | Prepare artifacts [Windows]
@@ -92,10 +92,12 @@ jobs:
          tar czvf ../../stage/${{ env.CRATE_NAME }}-${{ steps.extract_tag.outputs.tag }}-${{ matrix.name }} ${{ env.CRATE_NAME }}
          cd -
      - name: Post Setup | Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
        with:
          name: ${{ env.CRATE_NAME }}-${{ steps.extract_tag.outputs.tag }}-${{ matrix.name }}
          path: target/stage/*
+          # Idempotency: overwrite artefact by name if we're rerunning the deployment
+          overwrite: true

  # Create GitHub release with Rust build targets and release notes
  github_release:
@@ -109,18 +111,18 @@ jobs:
          fetch-depth: 0

      - name: Setup | Artifacts
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4

      - name: Setup | Extract version
        shell: bash
-        run: echo "##[set-output name=version;]$(echo ${GITHUB_REF#refs/tags/v})"
+        run: echo "version=${GITHUB_REF#refs/tags/v}" >> $GITHUB_OUTPUT
        id: extract_version

      - name: Setup | Release notes
        run: |
          cat CHANGELOG.md | sed -n '/^## ${{ steps.extract_version.outputs.version }}$/,/^## /p' | sed '$d' > RELEASE.md
      - name: Build | Publish
-        uses: softprops/action-gh-release@v1
+        uses: softprops/action-gh-release@v2
        with:
          files: ${{ env.CRATE_NAME }}-*/${{ env.CRATE_NAME }}-*
          body_path: RELEASE.md
@@ -131,24 +133,22 @@ jobs:
  publish:
    name: Publish to crates.io
    needs: github_release
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
    steps:
      - uses: actions/checkout@v4
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
            ~/.cargo/bin
-            cargo_target
          # We reuse the cache from our detailed test environment, if available
          key: detailed-test-${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
-          override: true
      - name: Publish crate
        env:
          CARGO_LOGIN_TOKEN: ${{ secrets.CARGO_LOGIN_TOKEN }}
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -11,32 +11,35 @@ permissions:

 jobs:
  publish:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
    steps:
      - uses: actions/checkout@v4
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
            ~/.cargo/bin
-            cargo_target
+            /tmp/cargo-install-target-dir
          # We reuse the cache from our detailed test environment, if available
          key: detailed-test-${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml') }}
      - name: Install toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
        with:
          toolchain: stable
-          override: true
      - name: Install mdbook
+        env:
+          CARGO_TARGET_DIR: "/tmp/cargo-install-target-dir"
        run: ./scripts/install-mdbook
      - name: Install mdbook extras
+        env:
+          CARGO_TARGET_DIR: "/tmp/cargo-install-target-dir"
        run: ./book/scripts/install-mdbook-extras
      - name: Build book
        run: ./scripts/build-book
      - name: Push docs
-        uses: JamesIves/github-pages-deploy-action@v4.4.3
+        uses: JamesIves/github-pages-deploy-action@v4
        with:
          branch: gh-pages
          folder: book/book
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,63 @@
 # Changelog

-## Unreleased
+## v1.20.0
+
+### Changed
+
+- MSRV (minimum supported rust version) is now 1.82.0 ([#227](https://github.com/tommilligan/mdbook-admonish/pull/227))
+- Collapsible blocks now show content in print view ([#228](https://github.com/tommilligan/mdbook-admonish/pull/228)). Thanks to [@igor-petruk](https://github.com/igor-petruk) for raising this issue.
+
+## v1.19.0
+
+### Changed
+
+- MSRV (minimum supported rust version) is now 1.76.0 ([#208](https://github.com/tommilligan/mdbook-admonish/pull/208))
+
+### Fixed
+
+- Fixed blocks not rendering correctly in indented list items. Thanks to [@JorelAli](https://github.com/JorelAli) for the bug report! ([#224](https://github.com/tommilligan/mdbook-admonish/pull/224))
+
+## v1.18.0
+
+### Changed
+
+- Add ARIA attributes to generated blocks. Thanks to [@toastal](https://github.com/toastal) for suggesting this feature! ([#195](https://github.com/tommilligan/mdbook-admonish/pull/195))
+  - Note: This subtly alters the emitted HTML, and could cause additional styles applied to blocks to break. Native `mdbook-admonish` styles are not affected.
+
+### Fixed
+
+- Fixed some valid configurations producing TOML serialization errors. Thanks to [@DianaNites](https://github.com/DianaNites) for reporting this! ([#197](https://github.com/tommilligan/mdbook-admonish/pull/197))
+
+## v1.17.1
+
+### Fixed
+
+- Removed a stray debug statement ([#186](https://github.com/tommilligan/mdbook-admonish/pull/186))
+
+## v1.17.0
+
+### Changed
+
+- Blocks should have key-value options separated by commas. Existing syntax remains is supported for back-compatibility. See [the documentation on Additional Options](https://tommilligan.github.io/mdbook-admonish/#additional-options) for more details ([#181](https://github.com/tommilligan/mdbook-admonish/pull/181))
+
+### Fixed
+
+- Titles contining `=` will now render correctly. Thanks to [@s00500](https://github.com/s00500) for the bug report! ([#181](https://github.com/tommilligan/mdbook-admonish/pull/181))
+
+## v1.16.0
+
+### Changed
+
+- MSRV (minimum supported rust version) is now 1.74.0 ([#175](https://github.com/tommilligan/mdbook-admonish/pull/175))
+- `custom` directives should now be configured under the `directive.custom` option. Existing `custom` configurations are supported for back compatibility ([#179](https://github.com/tommilligan/mdbook-admonish/pull/174))
+
+### Added
+
+- Make blocks `collapsible` on a per-directive basis. Thanks to [@yannickseurin](https://github.com/yannickseurin) for contributing this feature! ([#174](https://github.com/tommilligan/mdbook-admonish/pull/174))
+
+### Fixed
+
+- The `css_id_prefix` option now uses snake case for consistency (kebab case remains supported for back compatibility). Thanks to [@yannickseurin](https://github.com/yannickseurin) for fixing this! ([#173](https://github.com/tommilligan/mdbook-admonish/pull/173))

 ## 1.15.0

--- a/Cargo.lock
+++ b/Cargo.lock
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "mdbook-admonish"
-version = "1.15.0"
+version = "1.20.0"
 edition = "2021"
-rust-version = "1.66.0"
+rust-version = "1.76.0"

 authors = ["Tom Milligan <code@tommilligan.net>"]
 description = "A preprocessor for mdbook to add Material Design admonishments."
@@ -26,26 +26,23 @@ name = "mdbook_admonish"
 path = "src/lib.rs"

 [dependencies]
-anyhow = "1.0.75"
+anyhow = "1.0.86"
 # Note: clap 4.4 increases MSRV to 1.70.0 (2023-06-01)
 # To use MSRV supported dependencies, install using the lockfile with
 # `cargo install mdbook-admonish --locked`
-clap = { version = "4.3", default-features = false, features = ["std", "derive"], optional = true }
-env_logger = { version = "0.10", default-features = false, optional = true }
-log = "0.4.20"
-mdbook = "0.4.35"
-once_cell = "1.18.0"
+clap = { version = "4.5", default-features = false, features = ["std", "derive"], optional = true }
+env_logger = { version = "0.11", default-features = false, optional = true }
+log = "0.4.21"
+mdbook = "0.4.40"
+once_cell = "1.19.0"
 path-slash = "0.2.1"
-pulldown-cmark = "0.9.3"
-regex = "1.9.6"
-semver = "1.0.19"
-serde = { version = "1.0.188", features = ["derive"] }
-serde_json = "1.0.107"
-# The version of toml that mdbook uses internally (and uses in it's public api)
-# Only used for compatilibilty with the mdbook public api
-toml_mdbook = { package = "toml", version = "0.5.11" }
-toml = "0.8.1"
-toml_edit = { version = "0.20.1", optional = true }
+pulldown-cmark = "0.13"
+regex = "1.10.5"
+semver = "1.0.23"
+serde = { version = "1.0.203", features = ["derive"] }
+serde_json = "1.0.117"
+toml = "0.8.14"
+toml_edit = { version = "0.22.14", optional = true }
 hex_color = { version = "3.0.0", features = ["serde"] }

 [dev-dependencies]
--- a/README.md
+++ b/README.md
@@ -21,9 +21,11 @@ into this:

 Read the documentation [here](https://tommilligan.github.io/mdbook-admonish/), to see the actual examples in action. You can see the source in the [`./book`](./book) subdirectory.

-Other projects using mdbook-admonish:
+Projects using mdbook-admonish include:

- [The Rhai Book](https://rhai.rs/book/)
+- [The Rhai Book](https://rhai.rs/book/) ([source](https://github.com/rhaiscript/book))
+- [The Trunk Guide](https://trunkrs.dev/guide/) ([source](https://github.com/trunk-rs/trunk))
+- [PRQL language book](https://prql-lang.org/book/) ([source](https://github.com/PRQL/prql))

 ## Usage

--- a/book/book.toml
+++ b/book/book.toml
@@ -4,17 +4,16 @@ language = "en"
 multilingual = false
 src = "src"
 title = "The mdbook-admonish book"
+git-repository-url = "https://github.com/tommilligan/mdbook-admonish"

 [preprocessor]

 [preprocessor.admonish]
 command = "mdbook-admonish"
-assets_version = "3.0.1" # do not edit: managed by `mdbook-admonish install`
+assets_version = "3.1.0" # do not edit: managed by `mdbook-admonish install`

-[[preprocessor.admonish.custom]]
-directive = "expensive"
-icon = "./money-bag.svg"
-color = "#24ab38"
+[preprocessor.admonish.directive.custom]
+expensive = { icon = "./money-bag.svg", color = "#24ab38" }

 [preprocessor.toc]
 command = "mdbook-toc"
--- a/book/src/SUMMARY.md
+++ b/book/src/SUMMARY.md
@@ -2,3 +2,4 @@

 - [Overview](./overview.md)
 - [Reference](./reference.md)
+- [Examples](./examples.md)
--- a/book/src/examples.md
+++ b/book/src/examples.md
@@ -0,0 +1,15 @@
+# Examples
+
+## Combining multiple custom properties
+
+Note that the comma `,` is used to seperate custom options.
+
+````
+```admonish quote collapsible=true, title='A title that really <span style="color: #e70073">pops</span>'
+To really <b><span style="color: #e70073">grab</span></b> your reader's attention.
+```
+````
+
+```admonish quote collapsible=true, title='A title that really <span style="color: #e70073">pops</span>'
+To really <b><span style="color: #e70073">grab</span></b> your reader's attention.
+```
--- a/book/src/overview.md
+++ b/book/src/overview.md
@@ -78,14 +78,19 @@ You can also configure the build to fail loudly, by setting `on_failure = "bail"

 ### Additional Options

-You can pass additional options to each block. The options are structured as TOML key-value pairs.
+You can pass additional options to each block. Options are given like a [TOML Inline Table](https://toml.io/en/v1.0.0#inline-table), as key-value pairs separated by commas.
+
+`mdbook-admonish` parses options by wrapping your options in an inline table before parsing them, so please consult [The TOML Reference](https://toml.io) if you run into any syntax errors. Be aware that:
+
+- Key-value pairs must be separated with a comma `,`
+- TOML escapes must be escaped again - for instance, write `\"` as `\\"`.
+- For complex strings such as HTML, you may want to use a [literal string](https://toml.io/en/v1.0.0#string) to avoid complex escape sequences

 Note that some options can be passed globally, through the `default` section in `book.toml`. See the [configuration reference](./reference.md#booktoml-configuration) for more details.

 #### Custom title

-A custom title can be provided, contained in a double quoted TOML string.
-Note that TOML escapes must be escaped again - for instance, write `\"` as `\\"`.
+A custom title can be provided:

 ````
 ```admonish warning title="Data loss"
@@ -114,13 +119,13 @@ This will take a while, go and grab a drink of water.
 Markdown and HTML can be used in the inner content, as you'd expect:

 ````
-```admonish tip title="_Referencing_ and <i>dereferencing</i>"
+```admonish tip title='_Referencing_ and <i>dereferencing</i>'
 The opposite of *referencing* by using `&` is *dereferencing*, which is
 accomplished with the <span style="color: hotpink">dereference operator</span>, `*`.
 ```
 ````

-```admonish tip title="_Referencing_ and <i>dereferencing</i>"
+```admonish tip title='_Referencing_ and <i>dereferencing</i>'
 The opposite of *referencing* by using `&` is *dereferencing*, which is
 accomplished with the <span style="color: hotpink">dereference operator</span>, `*`.
 ```
@@ -148,7 +153,7 @@ print "Hello, world!"
 If you want to provide custom styling to a specific admonition, you can attach one or more custom classnames:

 ````
-```admonish note class="custom-0 custom-1"
+```admonish note title="Stylish", class="custom-0 custom-1"
 Styled with my custom CSS class.
 ```
 ````
@@ -173,7 +178,7 @@ with an appended number if multiple blocks would have the same id.
 Setting the `id` field will _ignore_ all other ids and the duplicate counter.

 ````
-```admonish info title="My Info" id="my-special-info"
+```admonish info title="My Info", id="my-special-info"
 Link to this block with `#my-special-info` instead of the default `#admonition-my-info`.
 ```
 ````
@@ -183,14 +188,14 @@ Link to this block with `#my-special-info` instead of the default `#admonition-m
 For a block to be initially collapsible, and then be openable, set `collapsible=true`:

 ````
-```admonish collapsible=true
+```admonish title="Sneaky", collapsible=true
 Content will be hidden initially.
 ```
 ````

 Will yield something like the following HTML, which you can then apply styles to:

-```admonish collapsible=true
+```admonish title="Sneaky", collapsible=true
 Content will be hidden initially.
 ```

--- a/book/src/reference.md
+++ b/book/src/reference.md
@@ -75,28 +75,50 @@ Subfields:
    - For the `html` renderer, the default value is `html`.
    - For all other renderers, the default value is `preserve`.

-### `custom`
+### `directive`

 Optional.

-Additional type of block to support.
-You must run `mdbook-admonish generate-custom` after updating these values, to generate the correct styles.
+Settings relating to each type of block.

-Add blocks using TOML's [Array of Tables](https://toml.io/en/v1.0.0#array-of-tables) notation:
+#### `builtin`
+
+Optional.
+
+Override the settings of a builtin directive.
+
+The subkey of `builtin` is the directive to override. This must be the first directive listed in the [Directives](#directives) section below, e.g. `warning` (not `caution` or other aliases).

 ```toml
-[[preprocessor.admonish.custom]]
-directive = "expensive"
+[preprocessor.admonish.directive.builtin.warning]
+collapsible = true
+```
+
+Subfields:
+
+- `collapsible` (optional): The default boolean value of the collapsible property for this type of block.
+
+#### `custom`
+
+Optional.
+
+Additional types of block to support. The subkey of `custom` is the new directive to support.
+
+You must run `mdbook-admonish generate-custom` after updating these values, to generate the correct styles.
+
+```toml
+[preprocessor.admonish.directive.custom.expensive]
 icon = "./money-bag.svg"
 color = "#24ab38"
+collapsible = true
 aliases = ["money", "cash", "budget"]
 ```

 Subfields:

- `directive`: The keyword to use this type of block.
 - `icon`: A filepath relative to the book root to load an SVG icon from.
 - `color`: An RGB hex encoded color to use for the icon.
+- `collapsible` (optional): The default boolean value of the collapsible property for this type of block.
 - `aliases` (optional): One or more alternative directives to use this block.
 - `title` (optional): The default title for this type of block. If not specified, defaults to the directive in title case. To give each alias a custom title, add multiple custom blocks.

--- a/compile_assets/.gitignore
+++ b/compile_assets/.gitignore
@@ -1,3 +1,5 @@
 /node_modules
 *.css
 *.css.map
+.yarn/
+.pnp*
--- a/compile_assets/package.json
+++ b/compile_assets/package.json
@@ -15,5 +15,6 @@
  },
  "devDependencies": {
    "prettier": "^3.0.3"
-  }
+  },
+  "packageManager": "yarn@4.8.1+sha512.bc946f2a022d7a1a38adfc15b36a66a3807a67629789496c3714dd1703d2e6c6b1c69ff9ec3b43141ac7a1dd853b7685638eb0074300386a59c18df351ef8ff6"
 }
--- a/compile_assets/scss/admonition.scss
+++ b/compile_assets/scss/admonition.scss
@@ -92,8 +92,9 @@ $admonitions: (
    0 0.2rem 1rem rgba(0, 0, 0, 0.05),
    0 0 0.1rem rgba(0, 0, 0, 0.1);

-  // [print]: Omit shadow as it may lead to rendering errors
+  // During print mode in browser, pdf renderer
  @media print {
+    // Omit shadow as it may lead to rendering errors
    box-shadow: none;
  }

@@ -200,6 +201,14 @@ a.admonition-anchor-link {
  }
 }

+// During print mode in browser, pdf renderer
+@media print {
+  // Expand collapsed sections to show details
+  details.admonition::details-content {
+    display: contents;
+  }
+}
+
 summary.admonition-title {
  details.admonition > &::after {
    position: absolute;
@@ -222,6 +231,12 @@ summary.admonition-title {
  details[open].admonition > &::after {
    transform: rotate(90deg);
  }
+
+  // Hide details marker for Safari that loves to show it anyway
+  // ref: https://github.com/tommilligan/mdbook-admonish/pull/185
+  &::-webkit-details-marker {
+    display: none;
+  }
 }

 :root {
--- a/compile_assets/yarn.lock
+++ b/compile_assets/yarn.lock
--- a/integration/book.toml
+++ b/integration/book.toml
@@ -9,7 +9,7 @@ title = "mdbook-admonish-integration"

 [preprocessor.admonish]
 command = "mdbook-admonish"
-assets_version = "3.0.2" # do not edit: managed by `mdbook-admonish install`
+assets_version = "3.1.0" # do not edit: managed by `mdbook-admonish install`
 after = ["links"]

 [[preprocessor.admonish.custom]]
--- a/integration/expected/book.toml
+++ b/integration/expected/book.toml
@@ -9,7 +9,7 @@ title = "mdbook-admonish-integration"

 [preprocessor.admonish]
 command = "mdbook-admonish"
-assets_version = "3.0.2" # do not edit: managed by `mdbook-admonish install`
+assets_version = "3.1.0" # do not edit: managed by `mdbook-admonish install`
 after = ["links"]

 [[preprocessor.admonish.custom]]
--- a/integration/expected/chapter_1_main.html
+++ b/integration/expected/chapter_1_main.html
@@ -1,90 +1,108 @@
                        <h1 id="chapter-1"><a class="header" href="#chapter-1">Chapter 1</a></h1>
-<div id="admonition-what-is-this" class="admonition admonish-abstract">
+<div id="admonition-what-is-this" class="admonition admonish-abstract" role="note" aria-labelledby="admonition-what-is-this-title">
 <div class="admonition-title">
+<div id="admonition-what-is-this-title">
 <p>What <i>is</i> this?</p>
-<p><a class="admonition-anchor-link" href="#admonition-what-is-this"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-what-is-this"></a>
 </div>
 <div>
 <p>This book acts as an integration test for <code>mdbook-admonish</code>.</p>
 <p>It verifies that <code>mdbook</code> post-processes our generated HTML in the way we expect.</p>
 </div>
 </div>
-<div id="admonition-note" class="admonition admonish-note">
+<div id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
 <div class="admonition-title">
+<div id="admonition-note-title">
 <p>Note</p>
-<p><a class="admonition-anchor-link" href="#admonition-note"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note"></a>
 </div>
 <div>
 <p>Simples</p>
 </div>
 </div>
-<div id="admonition-frog" class="admonition admonish-frog">
+<div id="admonition-frog" class="admonition admonish-frog" role="note" aria-labelledby="admonition-frog-title">
 <div class="admonition-title">
+<div id="admonition-frog-title">
 <p>Frog</p>
-<p><a class="admonition-anchor-link" href="#admonition-frog"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-frog"></a>
 </div>
 <div>
 <p>Custom frog directive</p>
 </div>
 </div>
-<div id="admonition-default" class="admonition admonish-warning">
+<div id="admonition-default" class="admonition admonish-warning" role="note">
 <div>
 <p>No title, only body</p>
 </div>
 </div>
-<div id="admonition-error-rendering-admonishment" class="admonition admonish-bug">
+<div id="admonition-error-rendering-admonishment" class="admonition admonish-bug" role="note" aria-labelledby="admonition-error-rendering-admonishment-title">
 <div class="admonition-title">
+<div id="admonition-error-rendering-admonishment-title">
 <p>Error rendering admonishment</p>
-<p><a class="admonition-anchor-link" href="#admonition-error-rendering-admonishment"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-error-rendering-admonishment"></a>
 </div>
 <div>
 <p>Failed with:</p>
-<pre><code class="language-log">TOML parsing error: TOML parse error at line 1, column 8
+<pre><code class="language-log">'title="' is not a valid directive or TOML key-value pair.
+
+TOML parsing error: TOML parse error at line 1, column 21
  |
-1 | title=&quot;
-  |        ^
+1 | config = { title=" }
+  |                     ^
 invalid basic string

 </code></pre>
 <p>Original markdown input:</p>
-<pre><code class="language-markdown">```admonish title=&quot;
+<pre><code class="language-markdown">```admonish title="
 No title, only body
 ```
 </code></pre>
 </div>
 </div>
-<details id="admonition-note-1" class="admonition admonish-note">
+<details id="admonition-note-1" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-1-title">
 <summary class="admonition-title">
+<div id="admonition-note-1-title">
 <p>Note</p>
-<p><a class="admonition-anchor-link" href="#admonition-note-1"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note-1"></a>
 </summary>
 <div>
 <p>Hidden on load</p>
 </div>
 </details>
-<div id="admonition-warning" class="admonition admonish-warning">
+<div id="admonition-warning" class="admonition admonish-warning" role="note" aria-labelledby="admonition-warning-title">
 <div class="admonition-title">
+<div id="admonition-warning-title">
 <p>Warning</p>
-<p><a class="admonition-anchor-link" href="#admonition-warning"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-warning"></a>
 </div>
 <div>
 <p>This is a commonly shared warning!</p>
 </div>
 </div>
-<div id="admonition-note-2" class="admonition admonish-note">
+<div id="admonition-note-2" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-2-title">
 <div class="admonition-title">
+<div id="admonition-note-2-title">
 <p>Note</p>
-<p><a class="admonition-anchor-link" href="#admonition-note-2"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note-2"></a>
 </div>
 <div>
 <pre><code class="language-bash">Nested code block
 </code></pre>
 </div>
 </div>
-<div id="admonition-note-3" class="admonition admonish-note">
+<div id="admonition-note-3" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-3-title">
 <div class="admonition-title">
+<div id="admonition-note-3-title">
 <p>Note</p>
-<p><a class="admonition-anchor-link" href="#admonition-note-3"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note-3"></a>
 </div>
 <div>
 <pre><pre class="playground"><code class="language-rust"><span class="boring">#![allow(unused)]
@@ -108,15 +126,34 @@ let x = 20;
 </li>
 <li>
 <p>Thing two</p>
-<div id="admonition-note-4" class="admonition admonish-note">
+<div id="admonition-note-4" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-4-title">
 <div class="admonition-title">
+<div id="admonition-note-4-title">
 <p>Note</p>
-<p><a class="admonition-anchor-link" href="#admonition-note-4"></a></p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note-4"></a>
 </div>
 <div>
 <p>Thing two</p>
 </div>
 </div>
+<ol>
+<li>
+<p>Thing two nested</p>
+<div id="admonition-note-5" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-5-title">
+<div class="admonition-title">
+<div id="admonition-note-5-title">
+<p>Note</p>
+</div>
+<a class="admonition-anchor-link" href="#admonition-note-5"></a>
+</div>
+<div>
+<p>Thing two nested (should not be a code block)
+Regression tests for https://github.com/tommilligan/mdbook-admonish/issues/223</p>
+</div>
+</div>
+</li>
+</ol>
 </li>
 <li>
 <p>Thing three</p>
--- a/integration/src/chapter_1.md
+++ b/integration/src/chapter_1.md
@@ -60,6 +60,13 @@ In a list:
   Thing two
   ```

+   1. Thing two nested
+   
+      ```admonish
+      Thing two nested (should not be a code block)
+      Regression tests for https://github.com/tommilligan/mdbook-admonish/issues/223
+      ```
+
 1. Thing three

   ```sh
--- a/scripts/install-mdbook
+++ b/scripts/install-mdbook
@@ -8,7 +8,7 @@ function eprintln() {
  >&2 echo "$1"
 }

-VERSION="0.4.35"
+VERSION="0.4.51"

 eprintln "Checking if mdbook $VERSION is installed"
 if [[ "$(mdbook --version)" != "mdbook v$VERSION" ]]; then
--- a/src/bin/assets/VERSION
+++ b/src/bin/assets/VERSION
@@ -1 +1 @@
-3.0.2
+3.1.0
--- a/src/bin/assets/mdbook-admonish.css
+++ b/src/bin/assets/mdbook-admonish.css
@@ -86,6 +86,11 @@ html :is(.admonition-title, summary.admonition-title):last-child {
  display: initial;
 }

+@media print {
+  details.admonition::details-content {
+    display: contents;
+  }
+}
 details.admonition > summary.admonition-title::after {
  position: absolute;
  top: 0.625em;
@@ -106,6 +111,9 @@ details.admonition > summary.admonition-title::after {
 details[open].admonition > summary.admonition-title::after {
  transform: rotate(90deg);
 }
+summary.admonition-title::-webkit-details-marker {
+  display: none;
+}

 :root {
  --md-details-icon: url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M8.59 16.58 13.17 12 8.59 7.41 10 6l6 6-6 6-1.41-1.42Z'/></svg>");
--- a/src/bin/mdbook-admonish.rs
+++ b/src/bin/mdbook-admonish.rs
@@ -125,7 +125,7 @@ struct Preprocessors {

 /// Load the plugin specific config as a toml string, for private deserialization.
 fn admonish_config_string(config: &Config) -> Result<String> {
-    Ok(toml_mdbook::to_string(
+    Ok(toml::to_string(
        &config
            .preprocessor
            .admonish
@@ -160,7 +160,7 @@ mod install {
        io::Write,
        path::PathBuf,
    };
-    use toml_edit::{self, Array, Document, Item, Table, Value};
+    use toml_edit::{self, Array, DocumentMut, Item, Table, Value};

    const ADMONISH_CSS_FILES: &[(&str, &[u8])] = &[(
        "mdbook-admonish.css",
@@ -196,7 +196,7 @@ mod install {
        let toml = fs::read_to_string(&config)
            .with_context(|| format!("can't read configuration file '{}'", config.display()))?;
        let mut doc = toml
-            .parse::<Document>()
+            .parse::<DocumentMut>()
            .context("configuration is not valid TOML")?;

        if let Ok(preprocessor) = preprocessor(&mut doc) {
@@ -259,7 +259,7 @@ A beautifully styled message.
    /// Return the `additional-css` field, initializing if required.
    ///
    /// Return `Err` if the existing configuration is unknown.
-    fn additional_css(doc: &mut Document) -> Result<&mut Array, ()> {
+    fn additional_css(doc: &mut DocumentMut) -> Result<&mut Array, ()> {
        let doc = doc.as_table_mut();

        let empty_table = Item::Table(Table::default());
@@ -283,7 +283,7 @@ A beautifully styled message.
    /// Return the preprocessor table for admonish, initializing if required.
    ///
    /// Return `Err` if the existing configuration is unknown.
-    fn preprocessor(doc: &mut Document) -> Result<&mut Item, ()> {
+    fn preprocessor(doc: &mut DocumentMut) -> Result<&mut Item, ()> {
        let doc = doc.as_table_mut();

        let empty_table = Item::Table(Table::default());
--- a/src/book_config.rs
+++ b/src/book_config.rs
@@ -4,26 +4,60 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::path::PathBuf;

-use crate::types::AdmonitionDefaults;
+use crate::types::{AdmonitionDefaults, BuiltinDirective, BuiltinDirectiveConfig};

 /// Loads the plugin configuration from mdbook internals.
 ///
 /// Roundtrips config to string, to avoid linking the plugin's internal version of toml
 /// to the one publically exposed by the mdbook library.
 pub(crate) fn admonish_config_from_context(ctx: &PreprocessorContext) -> Result<Config> {
-    let table: String = toml_mdbook::to_string(
+    let table: String = toml::to_string(
        ctx.config
            .get_preprocessor("admonish")
            .context("No configuration for mdbook-admonish in book.toml")?,
-    )?;
+    )
+    .context("Could not serialize mdbook-admonish config. This is a bug in the toml library.")?;
    admonish_config_from_str(&table)
 }

 pub(crate) fn admonish_config_from_str(data: &str) -> Result<Config> {
-    toml::from_str(data).context("Invalid mdbook-admonish configuration in book.toml")
+    let readonly: ConfigReadonly =
+        toml::from_str(data).context("Invalid mdbook-admonish configuration in book.toml")?;
+    let config = readonly.into();
+    log::debug!("Loaded admonish config: {:?}", config);
+    Ok(config)
 }

-#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+/// All valid input states including back-compatibility fields.
+///
+/// This struct deliberately does not implement Serialize as it never meant to
+/// be written, only converted to Config.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Default)]
+struct ConfigReadonly {
+    #[serde(default)]
+    pub on_failure: OnFailure,
+
+    #[serde(default)]
+    pub default: AdmonitionDefaults,
+
+    #[serde(default)]
+    pub renderer: HashMap<String, RendererConfig>,
+
+    #[serde(default)]
+    pub assets_version: Option<String>,
+
+    #[serde(default)]
+    pub custom: Vec<CustomDirectiveReadonly>,
+
+    #[serde(default)]
+    pub builtin: HashMap<BuiltinDirective, BuiltinDirectiveConfig>,
+
+    #[serde(default)]
+    pub directive: DirectiveConfig,
+}
+
+/// The canonical config format, without back-compatibility
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize, Default)]
 pub(crate) struct Config {
    #[serde(default)]
    pub on_failure: OnFailure,
@@ -38,14 +72,50 @@ pub(crate) struct Config {
    pub assets_version: Option<String>,

    #[serde(default)]
-    pub custom: Vec<CustomDirective>,
+    pub directive: DirectiveConfig,
+}
+
+impl From<ConfigReadonly> for Config {
+    fn from(other: ConfigReadonly) -> Self {
+        let ConfigReadonly {
+            on_failure,
+            default,
+            renderer,
+            assets_version,
+            custom,
+            builtin,
+            mut directive,
+        } = other;
+
+        // Merge deprecated config fields into main config object
+        directive.custom.extend(
+            custom
+                .into_iter()
+                .map(|CustomDirectiveReadonly { directive, config }| (directive, config)),
+        );
+        directive.builtin.extend(builtin);
+
+        Self {
+            on_failure,
+            default,
+            renderer,
+            assets_version,
+            directive,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize, Default)]
+pub(crate) struct DirectiveConfig {
+    #[serde(default)]
+    pub custom: HashMap<String, CustomDirective>,
+
+    #[serde(default)]
+    pub builtin: HashMap<BuiltinDirective, BuiltinDirectiveConfig>,
 }

 #[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
 pub(crate) struct CustomDirective {
-    /// The primary directive. Used for CSS classnames
-    pub directive: String,
-
    /// Path to an SVG file, relative to the book root.
    pub icon: PathBuf,

@@ -59,6 +129,20 @@ pub(crate) struct CustomDirective {
    /// Title to use, human readable.
    #[serde(default)]
    pub title: Option<String>,
+
+    /// Default collapsible value.
+    #[serde(default)]
+    pub collapsible: Option<bool>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+pub(crate) struct CustomDirectiveReadonly {
+    /// The primary directive. Used for CSS classnames
+    pub directive: String,
+
+    /// Path to an SVG file, relative to the book root.
+    #[serde(flatten)]
+    config: CustomDirective,
 }

 #[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
@@ -86,3 +170,156 @@ impl Default for OnFailure {
        Self::Continue
    }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    use crate::types::BuiltinDirective;
+
+    #[test]
+    fn empty_config_okay() -> Result<()> {
+        let actual = admonish_config_from_str("")?;
+        let expected = Config::default();
+        assert_eq!(actual, expected);
+        Ok(())
+    }
+
+    #[test]
+    fn css_id_prefix_kebab_case_allowed() -> Result<()> {
+        let expected = Config {
+            default: AdmonitionDefaults {
+                css_id_prefix: Some("flam-".to_owned()),
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        // Snake case okay
+        let actual = admonish_config_from_str(r#"default = { css_id_prefix = "flam-" }"#)?;
+        assert_eq!(actual, expected);
+
+        // Kebab case back-compat okay
+        let actual = admonish_config_from_str(r#"default = { css-id-prefix = "flam-" }"#)?;
+        assert_eq!(actual, expected);
+        Ok(())
+    }
+
+    #[test]
+    fn merge_old_and_new_custom_directives() -> Result<()> {
+        let serialized = r##"
+[directive.custom.purple]
+icon = "/tmp/test-directive.svg"
+color = "#9B4F96"
+aliases = ["test-directive-alias-0"]
+title = "Purple"
+collapsible = true
+
+[[custom]]
+directive = "blue"
+icon = "/tmp/test-directive.svg"
+color = "#0038A8"
+aliases = []
+title = "Blue"
+        "##;
+        let expected = Config {
+            directive: DirectiveConfig {
+                custom: HashMap::from([
+                    (
+                        "purple".to_owned(),
+                        CustomDirective {
+                            icon: PathBuf::from("/tmp/test-directive.svg"),
+                            color: hex_color::HexColor::from((155, 79, 150)),
+                            aliases: vec!["test-directive-alias-0".to_owned()],
+                            title: Some("Purple".to_owned()),
+                            collapsible: Some(true),
+                        },
+                    ),
+                    (
+                        "blue".to_owned(),
+                        CustomDirective {
+                            icon: PathBuf::from("/tmp/test-directive.svg"),
+                            color: hex_color::HexColor::from((0, 56, 168)),
+                            aliases: vec![],
+                            title: Some("Blue".to_owned()),
+                            collapsible: None,
+                        },
+                    ),
+                ]),
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        let actual = admonish_config_from_str(serialized)?;
+        assert_eq!(actual, expected);
+        Ok(())
+    }
+
+    #[test]
+    fn full_config_roundtrip() -> Result<()> {
+        let input = Config {
+            default: AdmonitionDefaults {
+                css_id_prefix: Some("flam-".to_owned()),
+                collapsible: true,
+                title: Some("".to_owned()),
+            },
+            assets_version: Some("1.1.1".to_owned()),
+            directive: DirectiveConfig {
+                custom: HashMap::from([(
+                    "test-directive".to_owned(),
+                    CustomDirective {
+                        icon: PathBuf::from("/tmp/test-directive.svg"),
+                        color: hex_color::HexColor::from((155, 79, 150)),
+                        aliases: vec!["test-directive-alias-0".to_owned()],
+                        title: Some("test-directive-title".to_owned()),
+                        collapsible: Some(true),
+                    },
+                )]),
+                builtin: HashMap::from([(
+                    BuiltinDirective::Warning,
+                    BuiltinDirectiveConfig {
+                        collapsible: Some(true),
+                    },
+                )]),
+            },
+            on_failure: OnFailure::Bail,
+            renderer: HashMap::from([(
+                "test-mode".to_owned(),
+                RendererConfig {
+                    render_mode: Some(RenderMode::Strip),
+                },
+            )]),
+        };
+
+        let expected = r##"on_failure = "bail"
+assets_version = "1.1.1"
+
+[default]
+title = ""
+collapsible = true
+css_id_prefix = "flam-"
+
+[renderer.test-mode]
+render_mode = "strip"
+
+[directive.custom.test-directive]
+icon = "/tmp/test-directive.svg"
+color = "#9B4F96"
+aliases = ["test-directive-alias-0"]
+title = "test-directive-title"
+collapsible = true
+
+[directive.builtin.warning]
+collapsible = true
+"##;
+
+        let serialized = toml::to_string(&input)?;
+        assert_eq!(serialized, expected);
+
+        let actual = admonish_config_from_str(&serialized)?;
+        assert_eq!(actual, input);
+        Ok(())
+    }
+}
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -1,11 +1,13 @@
+mod toml_wrangling;
 mod v1;
 mod v2;
+mod v3;

 /// Configuration as described by the instance of an admonition in markdown.
 ///
 /// This structure represents the configuration the user must provide in each
 /// instance.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Default)]
 pub(crate) struct InstanceConfig {
    pub(crate) directive: String,
    pub(crate) title: Option<String>,
@@ -35,20 +37,29 @@ impl InstanceConfig {
    /// - `Some(InstanceConfig)` if this is an `admonish` block
    pub fn from_info_string(info_string: &str) -> Option<Result<Self, String>> {
        let config_string = admonition_config_string(info_string)?;
+        Some(Self::from_admonish_config_string(config_string))
+    }

-        // If we succeed at parsing v2, return that. Otherwise hold onto the error
-        let config_v2_error = match v2::from_config_string(config_string) {
-            Ok(config) => return Some(Ok(config)),
-            Err(config) => config,
+    /// Parse an info string that is known to be for `admonish`.
+    fn from_admonish_config_string(config_string: &str) -> Result<Self, String> {
+        // If we succeed at parsing v3, return that. Otherwise hold onto the error
+        let config_v3_error = match v3::from_config_string(config_string) {
+            Ok(config) => return Ok(config),
+            Err(error) => error,
        };

-        Some(if let Ok(config) = v1::from_config_string(config_string) {
-            // If we succeed at parsing v1, return that.
-            Ok(config)
-        } else {
-            // Otherwise return our v2 error.
-            Err(config_v2_error)
-        })
+        // If we succeed at parsing v2, return that
+        if let Ok(config) = v2::from_config_string(config_string) {
+            return Ok(config);
+        };
+
+        // If we succeed at parsing v1, return that.
+        if let Ok(config) = v1::from_config_string(config_string) {
+            return Ok(config);
+        }
+
+        // Otherwise return our v3 error.
+        Err(config_v3_error)
    }
 }

@@ -90,5 +101,20 @@ mod test {
                collapsible: None,
            }
        );
+        // v3 syntax is supported
+        assert_eq!(
+            InstanceConfig::from_info_string(
+                r#"admonish title="Custom Title", type="question", id="my-id""#
+            )
+            .unwrap()
+            .unwrap(),
+            InstanceConfig {
+                directive: "question".to_owned(),
+                title: Some("Custom Title".to_owned()),
+                id: Some("my-id".to_owned()),
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            }
+        );
    }
 }
--- a/src/config/toml_wrangling.rs
+++ b/src/config/toml_wrangling.rs
@@ -0,0 +1,44 @@
+use once_cell::sync::Lazy;
+use regex::Regex;
+use serde::Deserialize;
+use std::fmt::Display;
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+pub(crate) struct UserInput {
+    #[serde(default)]
+    pub r#type: Option<String>,
+    #[serde(default)]
+    pub title: Option<String>,
+    #[serde(default)]
+    pub id: Option<String>,
+    #[serde(default)]
+    pub class: Option<String>,
+    #[serde(default)]
+    pub collapsible: Option<bool>,
+}
+
+impl UserInput {
+    pub fn classnames(&self) -> Vec<String> {
+        self.class
+            .as_ref()
+            .map(|class| {
+                class
+                    .split(' ')
+                    .filter(|classname| !classname.is_empty())
+                    .map(|classname| classname.to_owned())
+                    .collect()
+            })
+            .unwrap_or_default()
+    }
+}
+
+pub(crate) static RX_DIRECTIVE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r#"^[A-Za-z0-9_-]+$"#).expect("directive regex"));
+
+pub(crate) fn format_toml_parsing_error(error: impl Display) -> String {
+    format!("TOML parsing error: {error}")
+}
+
+pub(crate) fn format_invalid_directive(directive: &str, original_error: impl Display) -> String {
+    format!("'{directive}' is not a valid directive or TOML key-value pair.\n\n{original_error}")
+}
--- a/src/config/v2.rs
+++ b/src/config/v2.rs
@@ -1,30 +1,16 @@
+use super::toml_wrangling::{
+    format_invalid_directive, format_toml_parsing_error, UserInput, RX_DIRECTIVE,
+};
 use super::InstanceConfig;
 use once_cell::sync::Lazy;
 use regex::Regex;
-use serde::Deserialize;
-
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
-struct UserInput {
-    #[serde(default)]
-    r#type: Option<String>,
-    #[serde(default)]
-    title: Option<String>,
-    #[serde(default)]
-    id: Option<String>,
-    #[serde(default)]
-    class: Option<String>,
-    #[serde(default)]
-    collapsible: Option<bool>,
-}

 /// Transform our config string into valid toml
 fn bare_key_value_pairs_to_toml(pairs: &str) -> String {
    use regex::Captures;

-    static RX_BARE_KEY_ASSIGNMENT: Lazy<Regex> = Lazy::new(|| {
-        let bare_key = r#"[A-Za-z0-9_-]+"#;
-        Regex::new(&format!("(?:{bare_key}) *=")).expect("bare key assignment regex")
-    });
+    static RX_BARE_KEY_ASSIGNMENT: Lazy<Regex> =
+        Lazy::new(|| Regex::new(r#"(?:[A-Za-z0-9_-]+) *="#).expect("bare key assignment regex"));

    fn prefix_with_newline(captures: &Captures) -> String {
        format!(
@@ -41,10 +27,18 @@ fn bare_key_value_pairs_to_toml(pairs: &str) -> String {
        .into_owned()
 }

+fn user_input_from_config_toml(config_toml: &str) -> Result<UserInput, String> {
+    toml::from_str(config_toml).map_err(format_toml_parsing_error)
+}
+
 /// Parse and return the config assuming v2 format.
 ///
 /// Note that if an error occurs, a parsed struct that can be returned to
 /// show the error message will be returned.
+///
+/// The basic idea here is to accept space separated key-value pairs, break them
+/// onto separate lines, and then parse them as a TOML document.
+/// This breaks when values contain a literal '=' sign, for which v3 syntax should be used.
 pub(crate) fn from_config_string(config_string: &str) -> Result<InstanceConfig, String> {
    let config_toml = bare_key_value_pairs_to_toml(config_string);
    let config_toml = config_toml.trim();
@@ -52,7 +46,7 @@ pub(crate) fn from_config_string(config_string: &str) -> Result<InstanceConfig,
    let config: UserInput = match toml::from_str(config_toml) {
        Ok(config) => config,
        Err(error) => {
-            let original_error = Err(format!("TOML parsing error: {error}"));
+            let original_error = format_toml_parsing_error(error);

            // For ergonomic reasons, we allow users to specify the directive without
            // a key. So if parsing fails initially, take the first line,
@@ -62,17 +56,11 @@ pub(crate) fn from_config_string(config_string: &str) -> Result<InstanceConfig,
                None => (config_toml, ""),
            };

-            static RX_DIRECTIVE: Lazy<Regex> =
-                Lazy::new(|| Regex::new(r#"^[A-Za-z0-9_-]+$"#).expect("directive regex"));
-
            if !RX_DIRECTIVE.is_match(directive) {
-                return original_error;
+                return Err(format_invalid_directive(directive, original_error));
            }

-            let mut config: UserInput = match toml::from_str(config_toml) {
-                Ok(config) => config,
-                Err(_) => return original_error,
-            };
+            let mut config = user_input_from_config_toml(config_toml)?;
            config.r#type = Some(directive.to_owned());
            config
        }
@@ -102,97 +90,120 @@ mod test {
    use pretty_assertions::assert_eq;

    #[test]
-    fn test_from_config_string_v2() {
-        assert_eq!(
-            from_config_string("").unwrap(),
+    fn test_from_config_string_v2() -> Result<(), ()> {
+        fn check(config_string: &str, expected: InstanceConfig) -> Result<(), ()> {
+            let actual = match from_config_string(config_string) {
+                Ok(config) => config,
+                Err(error) => panic!("Expected config to be valid, got error:\n\n{}", error),
+            };
+            assert_eq!(actual, expected);
+            Ok(())
+        }
+
+        check(
+            "",
            InstanceConfig {
                directive: "".to_owned(),
                title: None,
                id: None,
                additional_classnames: Vec::new(),
                collapsible: None,
-            }
-        );
-        assert_eq!(
-            from_config_string(" ").unwrap(),
+            },
+        )?;
+        check(
+            " ",
            InstanceConfig {
                directive: "".to_owned(),
                title: None,
                id: None,
                additional_classnames: Vec::new(),
                collapsible: None,
-            }
-        );
-        assert_eq!(
-            from_config_string(
-                r#"type="note" class="additional classname" title="Никита" collapsible=true"#
-            )
-            .unwrap(),
+            },
+        )?;
+        check(
+            r#"type="note" class="additional classname" title="Никита" collapsible=true"#,
            InstanceConfig {
                directive: "note".to_owned(),
                title: Some("Никита".to_owned()),
                id: None,
                additional_classnames: vec!["additional".to_owned(), "classname".to_owned()],
                collapsible: Some(true),
-            }
-        );
+            },
+        )?;
        // Specifying unknown keys is okay, as long as they're valid
-        assert_eq!(
-            from_config_string(r#"unkonwn="but valid toml""#).unwrap(),
+        check(
+            r#"unkonwn="but valid toml""#,
            InstanceConfig {
                directive: "".to_owned(),
                title: None,
                id: None,
                additional_classnames: Vec::new(),
                collapsible: None,
-            }
-        );
+            },
+        )?;
        // Just directive is fine
-        assert_eq!(
-            from_config_string(r#"info"#).unwrap(),
+        check(
+            r#"info"#,
            InstanceConfig {
                directive: "info".to_owned(),
                title: None,
                id: None,
                additional_classnames: Vec::new(),
                collapsible: None,
-            }
-        );
+            },
+        )?;
        // Directive plus toml config
-        assert_eq!(
-            from_config_string(r#"info title="Information" collapsible=false"#).unwrap(),
+        check(
+            r#"info title="Information" collapsible=false"#,
            InstanceConfig {
                directive: "info".to_owned(),
                title: Some("Information".to_owned()),
                id: None,
                additional_classnames: Vec::new(),
                collapsible: Some(false),
-            }
-        );
+            },
+        )?;
        // Test custom id
-        assert_eq!(
-            from_config_string(r#"info title="My Info" id="my-info-custom-id""#).unwrap(),
+        check(
+            r#"info title="My Info" id="my-info-custom-id""#,
            InstanceConfig {
                directive: "info".to_owned(),
                title: Some("My Info".to_owned()),
                id: Some("my-info-custom-id".to_owned()),
                additional_classnames: Vec::new(),
                collapsible: None,
-            }
-        );
+            },
+        )?;
        // Directive after toml config is an error
        assert!(from_config_string(r#"title="Information" info"#).is_err());
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_from_config_string_invalid_directive() {
+        assert_eq!(
+            from_config_string(r#"oh!wow titlel=""#).unwrap_err(),
+            r#"'oh!wow' is not a valid directive or TOML key-value pair.
+
+TOML parsing error: TOML parse error at line 1, column 3
+  |
+1 | oh!wow 
+  |   ^
+expected `.`, `=`
+"#
+        );
    }

    #[test]
    fn test_from_config_string_invalid_toml_value() {
        assert_eq!(
            from_config_string(r#"note titlel=""#).unwrap_err(),
-            r#"TOML parsing error: TOML parse error at line 1, column 6
+            r#"TOML parsing error: TOML parse error at line 1, column 9
  |
-1 | note 
-  |      ^
-expected `.`, `=`
+1 | titlel="
+  |         ^
+invalid basic string
 "#
        );
    }
--- a/src/config/v3.rs
+++ b/src/config/v3.rs
@@ -0,0 +1,202 @@
+use super::toml_wrangling::{
+    format_invalid_directive, format_toml_parsing_error, UserInput, RX_DIRECTIVE,
+};
+use super::InstanceConfig;
+use serde::Deserialize;
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+struct Wrapper<T> {
+    config: T,
+}
+
+/// Transform our config string into valid toml
+fn bare_inline_table_to_toml(pairs: &str) -> String {
+    format!("config = {{ {pairs} }}")
+}
+
+fn user_input_from_config_string(config_string: &str) -> Result<UserInput, String> {
+    match toml::from_str::<Wrapper<_>>(&bare_inline_table_to_toml(config_string)) {
+        Ok(wrapper) => Ok(wrapper.config),
+        Err(error) => Err(format_toml_parsing_error(error)),
+    }
+}
+
+/// Parse and return the config assuming v3 format.
+///
+/// Note that if an error occurs, a parsed struct that can be returned to
+/// show the error message will be returned.
+///
+/// The basic idea here is to accept the inside of an inline table, wrap it,
+/// parse it, and then use the toml values.
+pub(crate) fn from_config_string(config_string: &str) -> Result<InstanceConfig, String> {
+    let config_string = config_string.trim();
+
+    let config = match user_input_from_config_string(config_string) {
+        Ok(config) => config,
+        Err(error) => {
+            // For ergonomic reasons, we allow users to specify the directive without
+            // a key. So if parsing fails initially, take the first word,
+            // use that as the directive, and reparse.
+            let (directive, config_string) = match config_string.split_once(' ') {
+                Some((directive, config_string)) => (directive.trim(), config_string.trim()),
+                None => (config_string, ""),
+            };
+
+            if !RX_DIRECTIVE.is_match(directive) {
+                return Err(format_invalid_directive(directive, error));
+            }
+
+            let mut config = user_input_from_config_string(config_string)?;
+            config.r#type = Some(directive.to_owned());
+            config
+        }
+    };
+
+    let additional_classnames = config.classnames();
+    Ok(InstanceConfig {
+        directive: config.r#type.unwrap_or_default(),
+        title: config.title,
+        id: config.id,
+        additional_classnames,
+        collapsible: config.collapsible,
+    })
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn test_from_config_string_v3() -> Result<(), ()> {
+        fn check(config_string: &str, expected: InstanceConfig) -> Result<(), ()> {
+            let actual = match from_config_string(config_string) {
+                Ok(config) => config,
+                Err(error) => {
+                    panic!("Expected config '{config_string}' to be valid, got error:\n\n{error}")
+                }
+            };
+            assert_eq!(actual, expected);
+            Ok(())
+        }
+
+        check(
+            "",
+            InstanceConfig {
+                directive: "".to_owned(),
+                title: None,
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+        check(
+            " ",
+            InstanceConfig {
+                directive: "".to_owned(),
+                title: None,
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+        check(
+            r#"type="note", class="additional classname", title="Никита", collapsible=true"#,
+            InstanceConfig {
+                directive: "note".to_owned(),
+                title: Some("Никита".to_owned()),
+                id: None,
+                additional_classnames: vec!["additional".to_owned(), "classname".to_owned()],
+                collapsible: Some(true),
+            },
+        )?;
+        // Specifying unknown keys is okay, as long as they're valid
+        check(
+            r#"unkonwn="but valid toml""#,
+            InstanceConfig {
+                directive: "".to_owned(),
+                title: None,
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+        // Just directive is fine
+        check(
+            r#"info"#,
+            InstanceConfig {
+                directive: "info".to_owned(),
+                title: None,
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+        // Directive plus toml config
+        check(
+            r#"info title="Information", collapsible=false"#,
+            InstanceConfig {
+                directive: "info".to_owned(),
+                title: Some("Information".to_owned()),
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: Some(false),
+            },
+        )?;
+        // Test custom id
+        check(
+            r#"info title="My Info", id="my-info-custom-id""#,
+            InstanceConfig {
+                directive: "info".to_owned(),
+                title: Some("My Info".to_owned()),
+                id: Some("my-info-custom-id".to_owned()),
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+        // Directive after toml config is an error
+        assert!(from_config_string(r#"title="Information" info"#).is_err());
+        // HTML with quotes inside content
+        // Note that we use toml literal (single quoted) strings here
+        check(
+            r#"info title='My <span class="emphasis">Title</span>'"#,
+            InstanceConfig {
+                directive: "info".to_owned(),
+                title: Some(r#"My <span class="emphasis">Title</span>"#.to_owned()),
+                id: None,
+                additional_classnames: Vec::new(),
+                collapsible: None,
+            },
+        )?;
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_from_config_string_invalid_directive() {
+        assert_eq!(
+            from_config_string(r#"oh!wow titlel=""#).unwrap_err(),
+            r#"'oh!wow' is not a valid directive or TOML key-value pair.
+
+TOML parsing error: TOML parse error at line 1, column 14
+  |
+1 | config = { oh!wow titlel=" }
+  |              ^
+expected `.`, `=`
+"#
+        );
+    }
+
+    #[test]
+    fn test_from_config_string_invalid_toml_value() {
+        assert_eq!(
+            from_config_string(r#"note titlel=""#).unwrap_err(),
+            r#"TOML parsing error: TOML parse error at line 1, column 22
+  |
+1 | config = { titlel=" }
+  |                      ^
+invalid basic string
+"#
+        );
+    }
+}
--- a/src/custom.rs
+++ b/src/custom.rs
@@ -12,8 +12,8 @@ use std::path::Path;
 static RX_COLLAPSE_NEWLINES: Lazy<Regex> =
    Lazy::new(|| Regex::new(r"[\r\n]+\s*").expect("invalid whitespace regex"));

-/// Do some simple things to make the svg input probably a valid data url
-/// Based on this gist: https://gist.github.com/jennyknuth/222825e315d45a738ed9d6e04c7a88d0
+// Do some simple things to make the svg input probably a valid data url
+// Based on this gist: https://gist.github.com/jennyknuth/222825e315d45a738ed9d6e04c7a88d0
 fn svg_to_data_url(svg: &str) -> String {
    const XMLNS: &str = r#"http://www.w3.org/2000/svg"#;
    //
@@ -70,7 +70,7 @@ fn directive_css(name: &str, svg_data: &str, tint: HexColor) -> String {
 #[doc(hidden)]
 pub fn css_from_config(book_dir: &Path, config: &str) -> Result<String> {
    let config = crate::book_config::admonish_config_from_str(config)?;
-    let custom_directives = config.custom;
+    let custom_directives = config.directive.custom;

    if custom_directives.is_empty() {
        return Err(anyhow!("No custom directives provided"));
@@ -78,10 +78,10 @@ pub fn css_from_config(book_dir: &Path, config: &str) -> Result<String> {

    log::info!("Loaded {} custom directives", custom_directives.len());
    let mut css = String::new();
-    for directive in custom_directives.iter() {
+    for (directive_name, directive) in custom_directives.iter() {
        let svg = fs::read_to_string(book_dir.join(&directive.icon))
            .with_context(|| format!("can't read icon file '{}'", directive.icon.display()))?;
-        css.push_str(&directive_css(&directive.directive, &svg, directive.color));
+        css.push_str(&directive_css(directive_name, &svg, directive.color));
    }
    Ok(css)
 }
--- a/src/markdown.rs
+++ b/src/markdown.rs
@@ -4,14 +4,13 @@ use pulldown_cmark::{CodeBlockKind::*, Event, Options, Parser, Tag};
 use crate::{
    book_config::OnFailure,
    parse::parse_admonition,
-    types::{AdmonitionDefaults, CustomDirectiveMap, RenderTextMode},
+    types::{Overrides, RenderTextMode},
 };

 pub(crate) fn preprocess(
    content: &str,
    on_failure: OnFailure,
-    admonition_defaults: &AdmonitionDefaults,
-    custom_directives: &CustomDirectiveMap,
+    overrides: &Overrides,
    render_text_mode: RenderTextMode,
 ) -> MdbookResult<String> {
    let mut id_counter = Default::default();
@@ -33,8 +32,7 @@ pub(crate) fn preprocess(

            let admonition = match parse_admonition(
                info_string.as_ref(),
-                admonition_defaults,
-                custom_directives,
+                overrides,
                span_content,
                on_failure,
                indent,
@@ -92,9 +90,12 @@ fn indent_of(content: &str, position: usize, max: usize) -> usize {

 #[cfg(test)]
 mod test {
-    use super::*;
    use pretty_assertions::assert_eq;

+    use crate::types::AdmonitionDefaults;
+
+    use super::*;
+
    #[test]
    fn indent_of_samples() {
        for (content, position, max, expected) in [
@@ -137,8 +138,7 @@ mod test {
        preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults::default(),
-            &CustomDirectiveMap::default(),
+            &Overrides::default(),
            RenderTextMode::Html,
        )
        .unwrap()
@@ -155,11 +155,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-note" class="admonition admonish-note">
+<div id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
 <div class="admonition-title">
+<div id="admonition-note-title">

 Note

+</div>
 <a class="admonition-anchor-link" href="#admonition-note"></a>
 </div>
 <div>
@@ -187,11 +189,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-note" class="admonition admonish-note">
+<div id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
 <div class="admonition-title">
+<div id="admonition-note-title">

 Note

+</div>
 <a class="admonition-anchor-link" href="#admonition-note"></a>
 </div>
 <div>
@@ -219,11 +223,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-warning" class="admonition admonish-warning">
+<div id="admonition-warning" class="admonition admonish-warning" role="note" aria-labelledby="admonition-warning-title">
 <div class="admonition-title">
+<div id="admonition-warning-title">

 Warning

+</div>
 <a class="admonition-anchor-link" href="#admonition-warning"></a>
 </div>
 <div>
@@ -249,11 +255,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-caution" class="admonition admonish-warning">
+<div id="admonition-caution" class="admonition admonish-warning" role="note" aria-labelledby="admonition-caution-title">
 <div class="admonition-title">
+<div id="admonition-caution-title">

 Caution

+</div>
 <a class="admonition-anchor-link" href="#admonition-caution"></a>
 </div>
 <div>
@@ -279,11 +287,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-read-this" class="admonition admonish-warning">
+<div id="admonition-read-this" class="admonition admonish-warning" role="note" aria-labelledby="admonition-read-this-title">
 <div class="admonition-title">
+<div id="admonition-read-this-title">

 Read **this**!

+</div>
 <a class="admonition-anchor-link" href="#admonition-read-this"></a>
 </div>
 <div>
@@ -373,11 +383,13 @@ hello

        let expected = r##"

-<div id="admonition-and-in-the-title" class="admonition admonish-note">
+<div id="admonition-and-in-the-title" class="admonition admonish-note" role="note" aria-labelledby="admonition-and-in-the-title-title">
 <div class="admonition-title">
+<div id="admonition-and-in-the-title-title">

 And "<i>in</i>" the title

+</div>
 <a class="admonition-anchor-link" href="#admonition-and-in-the-title"></a>
 </div>
 <div>
@@ -403,11 +415,13 @@ hello

        let expected = r##"

-<div id="admonition-trademark" class="admonition admonish-warning">
+<div id="admonition-trademark" class="admonition admonish-warning" role="note" aria-labelledby="admonition-trademark-title">
 <div class="admonition-title">
+<div id="admonition-trademark-title">

 Trademark™

+</div>
 <a class="admonition-anchor-link" href="#admonition-trademark"></a>
 </div>
 <div>
@@ -432,11 +446,13 @@ Will have bonus classnames

        let expected = r##"

-<div id="admonition-tip" class="admonition admonish-tip my-style other-style">
+<div id="admonition-tip" class="admonition admonish-tip my-style other-style" role="note" aria-labelledby="admonition-tip-title">
 <div class="admonition-title">
+<div id="admonition-tip-title">

 Tip

+</div>
 <a class="admonition-anchor-link" href="#admonition-tip"></a>
 </div>
 <div>
@@ -460,11 +476,13 @@ Will have bonus classnames

        let expected = r##"

-<div id="admonition-developers-dont-want-you-to-know-this-one-weird-tip" class="admonition admonish-tip my-style other-style">
+<div id="admonition-developers-dont-want-you-to-know-this-one-weird-tip" class="admonition admonish-tip my-style other-style" role="note" aria-labelledby="admonition-developers-dont-want-you-to-know-this-one-weird-tip-title">
 <div class="admonition-title">
+<div id="admonition-developers-dont-want-you-to-know-this-one-weird-tip-title">

 Developers don't want you to know this one weird tip!

+</div>
 <a class="admonition-anchor-link" href="#admonition-developers-dont-want-you-to-know-this-one-weird-tip"></a>
 </div>
 <div>
@@ -487,7 +505,7 @@ Will have bonus classnames

        let expected = r#"

-<div id="admonition-default" class="admonition admonish-note">
+<div id="admonition-default" class="admonition admonish-note" role="note">
 <div>


@@ -513,11 +531,13 @@ Content one.

        let expected = r##"

-<div id="admonition-my-note" class="admonition admonish-note">
+<div id="admonition-my-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-my-note-title">
 <div class="admonition-title">
+<div id="admonition-my-note-title">

 My Note

+</div>
 <a class="admonition-anchor-link" href="#admonition-my-note"></a>
 </div>
 <div>
@@ -528,11 +548,13 @@ Content zero.
 </div>


-<div id="admonition-my-note-1" class="admonition admonish-note">
+<div id="admonition-my-note-1" class="admonition admonish-note" role="note" aria-labelledby="admonition-my-note-1-title">
 <div class="admonition-title">
+<div id="admonition-my-note-1-title">

 My Note

+</div>
 <a class="admonition-anchor-link" href="#admonition-my-note-1"></a>
 </div>
 <div>
@@ -556,11 +578,13 @@ Bonus content!

        let expected = r##"

-<div id="admonition-article-heading" class="admonition admonish-tip my other-style">
+<div id="admonition-article-heading" class="admonition admonish-tip my other-style" role="note" aria-labelledby="admonition-article-heading-title">
 <div class="admonition-title">
+<div id="admonition-article-heading-title">

 Article Heading

+</div>
 <a class="admonition-anchor-link" href="#admonition-article-heading"></a>
 </div>
 <div>
@@ -584,11 +608,13 @@ Bonus content!

        let expected = r##"

-<div id="admonition-error-rendering-admonishment" class="admonition admonish-bug">
+<div id="admonition-error-rendering-admonishment" class="admonition admonish-bug" role="note" aria-labelledby="admonition-error-rendering-admonishment-title">
 <div class="admonition-title">
+<div id="admonition-error-rendering-admonishment-title">

 Error rendering admonishment

+</div>
 <a class="admonition-anchor-link" href="#admonition-error-rendering-admonishment"></a>
 </div>
 <div>
@@ -596,10 +622,12 @@ Error rendering admonishment
 Failed with:

 ```log
-TOML parsing error: TOML parse error at line 1, column 8
+'title="' is not a valid directive or TOML key-value pair.
+
+TOML parsing error: TOML parse error at line 1, column 21
  |
-1 | title="
-  |        ^
+1 | config = { title=" }
+  |                     ^
 invalid basic string

 ```
@@ -631,8 +659,7 @@ Bonus content!
            preprocess(
                content,
                OnFailure::Bail,
-                &AdmonitionDefaults::default(),
-                &CustomDirectiveMap::default(),
+                &Overrides::default(),
                RenderTextMode::Html
            )
            .unwrap_err()
@@ -659,8 +686,7 @@ x = 20;
            preprocess(
                content,
                OnFailure::Bail,
-                &AdmonitionDefaults::default(),
-                &CustomDirectiveMap::default(),
+                &Overrides::default(),
                RenderTextMode::Strip
            )
            .unwrap(),
@@ -686,11 +712,13 @@ Hidden

        let expected = r##"

-<details id="admonition-note" class="admonition admonish-note">
+<details id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
 <summary class="admonition-title">
+<div id="admonition-note-title">

 Note

+</div>
 <a class="admonition-anchor-link" href="#admonition-note"></a>
 </summary>
 <div>
@@ -715,11 +743,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-admonish" class="admonition admonish-note">
+<div id="admonition-admonish" class="admonition admonish-note" role="note" aria-labelledby="admonition-admonish-title">
 <div class="admonition-title">
+<div id="admonition-admonish-title">

 Admonish

+</div>
 <a class="admonition-anchor-link" href="#admonition-admonish"></a>
 </div>
 <div>
@@ -734,12 +764,14 @@ Text
        let preprocess_result = preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults {
-                title: Some("Admonish".to_owned()),
-                css_id_prefix: None,
-                collapsible: false,
+            &Overrides {
+                book: AdmonitionDefaults {
+                    title: Some("Admonish".to_owned()),
+                    css_id_prefix: None,
+                    collapsible: false,
+                },
+                ..Default::default()
            },
-            &CustomDirectiveMap::default(),
            RenderTextMode::Html,
        )
        .unwrap();
@@ -757,7 +789,7 @@ Text

        let expected = r#"# Chapter

-<div id="admonition-default" class="admonition admonish-note">
+<div id="admonition-default" class="admonition admonish-note" role="note">
 <div>

 A simple admonition.
@@ -770,12 +802,14 @@ Text
        let preprocess_result = preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults {
-                title: Some("Admonish".to_owned()),
-                css_id_prefix: None,
-                collapsible: false,
+            &Overrides {
+                book: AdmonitionDefaults {
+                    title: Some("Admonish".to_owned()),
+                    css_id_prefix: None,
+                    collapsible: false,
+                },
+                ..Default::default()
            },
-            &CustomDirectiveMap::default(),
            RenderTextMode::Html,
        )
        .unwrap();
@@ -793,7 +827,7 @@ Text

        let expected = r#"# Chapter

-<div id="admonition-default" class="admonition admonish-note">
+<div id="admonition-default" class="admonition admonish-note" role="note">
 <div>

 A simple admonition.
@@ -817,11 +851,13 @@ Text

        let expected = r##"# Chapter

-<div id="yay-custom-id" class="admonition admonish-success">
+<div id="yay-custom-id" class="admonition admonish-success" role="note" aria-labelledby="yay-custom-id-title">
 <div class="admonition-title">
+<div id="yay-custom-id-title">

 Check

+</div>
 <a class="admonition-anchor-link" href="#yay-custom-id"></a>
 </div>
 <div>
@@ -847,11 +883,13 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-check" class="admonition admonish-success">
+<div id="admonition-check" class="admonition admonish-success" role="note" aria-labelledby="admonition-check-title">
 <div class="admonition-title">
+<div id="admonition-check-title">

 Check

+</div>
 <a class="admonition-anchor-link" href="#admonition-check"></a>
 </div>
 <div>
@@ -877,17 +915,54 @@ Text

        let expected = r##"# Chapter

-<div id="admonition-check-mark" class="admonition admonish-success">
+<div id="admonition-check-mark" class="admonition admonish-success" role="note" aria-labelledby="admonition-check-mark-title">
 <div class="admonition-title">
+<div id="admonition-check-mark-title">

 Check Mark

+</div>
 <a class="admonition-anchor-link" href="#admonition-check-mark"></a>
 </div>
 <div>

 A simple admonition.

+</div>
+</div>
+Text
+"##;
+
+        assert_eq!(expected, prep(content));
+    }
+
+    #[test]
+    fn title_and_content_with_html() {
+        // Note that we use toml literal (single quoted) strings here
+        // and the fact we have an equals sign in the value does not cause
+        // us to break (because we're using v3 syntax, not v2)
+        let content = r#"# Chapter
+```admonish success title='Check <span class="emphasis">Mark</span>'
+A <span class="emphasis">simple</span> admonition.
+```
+Text
+"#;
+
+        let expected = r##"# Chapter
+
+<div id="admonition-check-mark" class="admonition admonish-success" role="note" aria-labelledby="admonition-check-mark-title">
+<div class="admonition-title">
+<div id="admonition-check-mark-title">
+
+Check <span class="emphasis">Mark</span>
+
+</div>
+<a class="admonition-anchor-link" href="#admonition-check-mark"></a>
+</div>
+<div>
+
+A <span class="emphasis">simple</span> admonition.
+
 </div>
 </div>
 Text
@@ -907,11 +982,13 @@ Text

        let expected = r##"# Chapter

-<div id="info" class="admonition admonish-info">
+<div id="info" class="admonition admonish-info" role="note" aria-labelledby="info-title">
 <div class="admonition-title">
+<div id="info-title">

 Info

+</div>
 <a class="admonition-anchor-link" href="#info"></a>
 </div>
 <div>
@@ -926,12 +1003,14 @@ Text
        let preprocess_result = preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults {
-                title: Some("Info".to_owned()),
-                css_id_prefix: Some("".to_owned()),
-                collapsible: false,
+            &Overrides {
+                book: AdmonitionDefaults {
+                    title: Some("Info".to_owned()),
+                    css_id_prefix: Some("".to_owned()),
+                    collapsible: false,
+                },
+                ..Default::default()
            },
-            &CustomDirectiveMap::default(),
            RenderTextMode::Html,
        )
        .unwrap();
@@ -949,11 +1028,13 @@ Text

        let expected = r##"# Chapter

-<div id="prefix-my-title" class="admonition admonish-info">
+<div id="prefix-my-title" class="admonition admonish-info" role="note" aria-labelledby="prefix-my-title-title">
 <div class="admonition-title">
+<div id="prefix-my-title-title">

 My Title

+</div>
 <a class="admonition-anchor-link" href="#prefix-my-title"></a>
 </div>
 <div>
@@ -968,12 +1049,14 @@ Text
        let preprocess_result = preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults {
-                title: Some("Info".to_owned()),
-                css_id_prefix: Some("prefix-".to_owned()),
-                collapsible: false,
+            &Overrides {
+                book: AdmonitionDefaults {
+                    title: Some("Info".to_owned()),
+                    css_id_prefix: Some("prefix-".to_owned()),
+                    collapsible: false,
+                },
+                ..Default::default()
            },
-            &CustomDirectiveMap::default(),
            RenderTextMode::Html,
        )
        .unwrap();
@@ -991,11 +1074,13 @@ Text

        let expected = r##"# Chapter

-<div id="my-section-id" class="admonition admonish-info">
+<div id="my-section-id" class="admonition admonish-info" role="note" aria-labelledby="my-section-id-title">
 <div class="admonition-title">
+<div id="my-section-id-title">

 My Title

+</div>
 <a class="admonition-anchor-link" href="#my-section-id"></a>
 </div>
 <div>
@@ -1010,12 +1095,14 @@ Text
        let preprocess_result = preprocess(
            content,
            OnFailure::Continue,
-            &AdmonitionDefaults {
-                title: Some("Info".to_owned()),
-                css_id_prefix: Some("ignored-prefix-".to_owned()),
-                collapsible: false,
+            &Overrides {
+                book: AdmonitionDefaults {
+                    title: Some("Info".to_owned()),
+                    css_id_prefix: Some("ignored-prefix-".to_owned()),
+                    collapsible: false,
+                },
+                ..Default::default()
            },
-            &CustomDirectiveMap::default(),
            RenderTextMode::Html,
        )
        .unwrap();
@@ -1056,17 +1143,19 @@ Text
 1. Thing two

   
-   <div id="admonition-note" class="admonition admonish-note">
+   <div id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
   <div class="admonition-title">
+   <div id="admonition-note-title">
   
   Note
   
+   </div>
   <a class="admonition-anchor-link" href="#admonition-note"></a>
   </div>
   <div>
-   
-      Thing two
-   
+
+   Thing two
+
   </div>
   </div>

@@ -1079,4 +1168,97 @@ Text

        assert_eq!(expected, prep(content));
    }
+
+    // Regression test for https://github.com/tommilligan/mdbook-admonish/issues/223
+    #[test]
+    fn nested_list_should_not_render_indented_code_block() {
+        let content = r#"# Chapter
+
+- Level one
+
+  ```admonish
+  Thing one
+  line two
+  ```
+
+  - Level two
+
+    ```admonish
+    Thing two
+    line two
+    ```
+
+    - Level three
+
+      ```admonish
+      Thing three
+      line two
+      ```
+"#;
+
+        let expected = r##"# Chapter
+
+- Level one
+
+  
+  <div id="admonition-note" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-title">
+  <div class="admonition-title">
+  <div id="admonition-note-title">
+  
+  Note
+  
+  </div>
+  <a class="admonition-anchor-link" href="#admonition-note"></a>
+  </div>
+  <div>
+
+  Thing one
+  line two
+
+  </div>
+  </div>
+
+  - Level two
+
+    
+    <div id="admonition-note-1" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-1-title">
+    <div class="admonition-title">
+    <div id="admonition-note-1-title">
+    
+    Note
+    
+    </div>
+    <a class="admonition-anchor-link" href="#admonition-note-1"></a>
+    </div>
+    <div>
+
+    Thing two
+    line two
+
+    </div>
+    </div>
+
+    - Level three
+
+      
+      <div id="admonition-note-2" class="admonition admonish-note" role="note" aria-labelledby="admonition-note-2-title">
+      <div class="admonition-title">
+      <div id="admonition-note-2-title">
+      
+      Note
+      
+      </div>
+      <a class="admonition-anchor-link" href="#admonition-note-2"></a>
+      </div>
+      <div>
+
+      Thing three
+      line two
+
+      </div>
+      </div>
+"##;
+
+        assert_eq!(expected, prep(content));
+    }
 }
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -5,7 +5,7 @@ use crate::{
    book_config::OnFailure,
    render::Admonition,
    resolve::AdmonitionMeta,
-    types::{AdmonitionDefaults, BuiltinDirective, CssId, CustomDirectiveMap},
+    types::{BuiltinDirective, CssId, Overrides},
 };

 /// Given the content in the span of the code block, and the info string,
@@ -19,8 +19,7 @@ use crate::{
 /// If the code block is not an admonition, return `None`.
 pub(crate) fn parse_admonition<'a>(
    info_string: &'a str,
-    admonition_defaults: &'a AdmonitionDefaults,
-    custom_directives: &'a CustomDirectiveMap,
+    overrides: &'a Overrides,
    content: &'a str,
    on_failure: OnFailure,
    indent: usize,
@@ -28,8 +27,7 @@ pub(crate) fn parse_admonition<'a>(
    // We need to know fence details anyway for error messages
    let extracted = extract_admonish_body(content);

-    let info =
-        AdmonitionMeta::from_info_string(info_string, admonition_defaults, custom_directives)?;
+    let info = AdmonitionMeta::from_info_string(info_string, overrides)?;
    let info = match info {
        Ok(info) => info,
        Err(message) => {
--- a/src/preprocessor.rs
+++ b/src/preprocessor.rs
@@ -8,7 +8,7 @@ use mdbook::{
 use crate::{
    book_config::{admonish_config_from_context, Config, RenderMode},
    markdown::preprocess,
-    types::{CustomDirectiveMap, RenderTextMode},
+    types::{Overrides, RenderTextMode},
 };

 pub struct Admonish;
@@ -22,11 +22,21 @@ impl Preprocessor for Admonish {
        let config = admonish_config_from_context(ctx)?;
        ensure_compatible_assets_version(&config)?;

-        let custom_directives =
-            CustomDirectiveMap::from_configs(config.custom.into_iter().map(Into::into));
+        let custom_directives = config
+            .directive
+            .custom
+            .into_iter()
+            .map(Into::into)
+            .collect();
        let on_failure = config.on_failure;
        let admonition_defaults = config.default;

+        let overrides = Overrides {
+            book: admonition_defaults,
+            custom: custom_directives,
+            builtin: config.directive.builtin,
+        };
+
        // Load what rendering we should do from config, falling back to a default
        let render_mode = config
            .renderer
@@ -55,16 +65,11 @@ impl Preprocessor for Admonish {

            if let BookItem::Chapter(ref mut chapter) = *item {
                res = Some(
-                    preprocess(
-                        &chapter.content,
-                        on_failure,
-                        &admonition_defaults,
-                        &custom_directives,
-                        render_text_mode,
-                    )
-                    .map(|md| {
-                        chapter.content = md;
-                    }),
+                    preprocess(&chapter.content, on_failure, &overrides, render_text_mode).map(
+                        |md| {
+                            chapter.content = md;
+                        },
+                    ),
                );
            }
        });
@@ -173,11 +178,13 @@ x = 20;
 "#;
        let expected_content = r##"

-<div id="admonition-title" class="admonition admonish-note">
+<div id="admonition-title" class="admonition admonish-note" role="note" aria-labelledby="admonition-title-title">
 <div class="admonition-title">
+<div id="admonition-title-title">

 Title

+</div>
 <a class="admonition-anchor-link" href="#admonition-title"></a>
 </div>
 <div>
--- a/src/render.rs
+++ b/src/render.rs
@@ -35,9 +35,9 @@ impl<'a> Admonition<'a> {
        }
    }

-    pub(crate) fn html(&self, id_counter: &mut HashMap<String, usize>) -> String {
+    pub(crate) fn html(self, id_counter: &mut HashMap<String, usize>) -> String {
        let anchor_id = match &self.css_id {
-            CssId::Verbatim(id) => Cow::Borrowed(id),
+            CssId::Verbatim(id) => Cow::Borrowed(id.as_str()),
            CssId::Prefix(prefix) => {
                let id = unique_id_from_content(
                    if !self.title.is_empty() {
@@ -56,53 +56,79 @@ impl<'a> Admonition<'a> {
        let content = &self.content;
        let indent = " ".repeat(self.indent);

-        let title_block = if self.collapsible { "summary" } else { "div" };
-
-        let title_html = if !title.is_empty() {
-            Cow::Owned(format!(
-                r##"{indent}<{title_block} class="admonition-title">
+        let (titlebar_html, title_id) = if !title.is_empty() {
+            let titlebar_element = if self.collapsible { "summary" } else { "div" };
+            let title_id = format!("{anchor_id}-title");
+            let titlebar_html = Cow::Owned(format!(
+                r##"{indent}<{titlebar_element} class="admonition-title">
+{indent}<div id="{title_id}">
 {indent}
 {indent}{title}
 {indent}
+{indent}</div>
 {indent}<a class="admonition-anchor-link" href="#{anchor_id}"></a>
-{indent}</{title_block}>
+{indent}</{titlebar_element}>
 "##
-            ))
+            ));
+            (titlebar_html, Some(title_id))
        } else {
-            Cow::Borrowed("")
+            (Cow::Borrowed(""), None)
        };

-        let mut additional_class = format!("admonish-{}", self.directive);
-        if !self.additional_classnames.is_empty() {
-            for additional_classname in &self.additional_classnames {
-                additional_class.push(' ');
-                additional_class.push_str(additional_classname);
-            }
-        }
+        let mut classes = vec![
+            "admonition".to_owned(),
+            format!("admonish-{}", self.directive),
+        ];
+        classes.extend(self.additional_classnames);
+        let classes = classes.join(" ");

-        let admonition_block = if self.collapsible { "details" } else { "div" };
+        let mut attributes = vec![
+            ("id", anchor_id),
+            ("class", Cow::Owned(classes)),
+            ("role", Cow::Borrowed("note")),
+        ];
+        if let Some(title_id) = title_id {
+            attributes.push(("aria-labelledby", Cow::Owned(title_id)));
+        }
+        let attributes = join_attributes(&attributes);
+
+        let admonition_element = if self.collapsible { "details" } else { "div" };
        // Notes on the HTML template:
        // - the additional whitespace around the content are deliberate
        //   In line with the commonmark spec, this allows the inner content to be
        //   rendered as markdown paragraphs.
+        // - We should not indent the inner content, as it retains the indent
+        //   it is written with.
        format!(
            r#"
-{indent}<{admonition_block} id="{anchor_id}" class="admonition {additional_class}">
-{title_html}{indent}<div>
-{indent}
-{indent}{content}
-{indent}
+{indent}<{admonition_element} {attributes}>
+{titlebar_html}{indent}<div>
+
+{content}
+
 {indent}</div>
-{indent}</{admonition_block}>"#,
+{indent}</{admonition_element}>"#,
        )
    }

    /// Strips all admonish syntax, leaving the plain content of the block.
-    pub(crate) fn strip(&self) -> String {
+    pub(crate) fn strip(self) -> String {
        // Add in newlines to preserve line numbering for test output
        // These replace the code fences we stripped out
        format!("\n{}\n", self.content)
    }
 }

+fn join_attributes(attributes: &[(impl AsRef<str>, impl AsRef<str>)]) -> String {
+    let mut buffer = String::new();
+    for (key, value) in attributes {
+        buffer.push_str(key.as_ref());
+        buffer.push_str(r#"=""#);
+        buffer.push_str(value.as_ref());
+        buffer.push_str(r#"" "#);
+    }
+    buffer.pop();
+    buffer
+}
+
 const ANCHOR_ID_DEFAULT: &str = "default";
--- a/src/resolve.rs
+++ b/src/resolve.rs
@@ -1,7 +1,5 @@
 use crate::config::InstanceConfig;
-use crate::types::{
-    AdmonitionDefaults, BuiltinDirective, CssId, CustomDirective, CustomDirectiveMap,
-};
+use crate::types::{BuiltinDirective, CssId, CustomDirective, CustomDirectiveMap, Overrides};
 use std::fmt;
 use std::str::FromStr;

@@ -59,20 +57,15 @@ impl Directive {
 impl AdmonitionMeta {
    pub fn from_info_string(
        info_string: &str,
-        defaults: &AdmonitionDefaults,
-        custom_directives: &CustomDirectiveMap,
+        overrides: &Overrides,
    ) -> Option<Result<Self, String>> {
        InstanceConfig::from_info_string(info_string)
-            .map(|raw| raw.map(|raw| Self::resolve(raw, defaults, custom_directives)))
+            .map(|raw| raw.map(|raw| Self::resolve(raw, overrides)))
    }

    /// Combine the per-admonition configuration with global defaults (and
    /// other logic) to resolve the values needed for rendering.
-    fn resolve(
-        raw: InstanceConfig,
-        defaults: &AdmonitionDefaults,
-        custom_directives: &CustomDirectiveMap,
-    ) -> Self {
+    fn resolve(raw: InstanceConfig, overrides: &Overrides) -> Self {
        let InstanceConfig {
            directive: raw_directive,
            title,
@@ -82,10 +75,27 @@ impl AdmonitionMeta {
        } = raw;

        // Use values from block, else load default value
-        let title = title.or_else(|| defaults.title.clone());
-        let collapsible = collapsible.unwrap_or(defaults.collapsible);
+        let title = title.or_else(|| overrides.book.title.clone());

-        let directive = Directive::from_str(custom_directives, &raw_directive);
+        let directive = Directive::from_str(&overrides.custom, &raw_directive);
+
+        let collapsible = match directive {
+            // If the directive is a builin one, use collapsible from block, else use default
+            // value of the builtin directive, else use global default value
+            Ok(Directive::Builtin(directive)) => collapsible.unwrap_or(
+                overrides
+                    .builtin
+                    .get(&directive)
+                    .and_then(|config| config.collapsible)
+                    .unwrap_or(overrides.book.collapsible),
+            ),
+            // If the directive is a custom one, use collapsible from block, else use default
+            // value of the custom directive, else use global default value
+            Ok(Directive::Custom(ref custom_dir)) => {
+                collapsible.unwrap_or(custom_dir.collapsible.unwrap_or(overrides.book.collapsible))
+            }
+            Err(_) => collapsible.unwrap_or(overrides.book.collapsible),
+        };

        // Load the directive (and title, if one still not given)
        let (directive, title) = match (directive, title) {
@@ -100,7 +110,8 @@ impl AdmonitionMeta {
        } else {
            const DEFAULT_CSS_ID_PREFIX: &str = "admonition-";
            CssId::Prefix(
-                defaults
+                overrides
+                    .book
                    .css_id_prefix
                    .clone()
                    .unwrap_or_else(|| DEFAULT_CSS_ID_PREFIX.to_owned()),
@@ -141,6 +152,10 @@ fn uppercase_first(input: &str) -> String {

 #[cfg(test)]
 mod test {
+    use std::collections::HashMap;
+
+    use crate::types::{AdmonitionDefaults, BuiltinDirectiveConfig};
+
    use super::*;
    use pretty_assertions::assert_eq;

@@ -167,8 +182,7 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &Default::default(),
-                &CustomDirectiveMap::default(),
+                &Overrides::default(),
            ),
            AdmonitionMeta {
                directive: "note".to_owned(),
@@ -191,12 +205,14 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &AdmonitionDefaults {
-                    title: Some("Important!!!".to_owned()),
-                    css_id_prefix: Some("custom-prefix-".to_owned()),
-                    collapsible: true,
-                },
-                &CustomDirectiveMap::default(),
+                &Overrides {
+                    book: AdmonitionDefaults {
+                        title: Some("Important!!!".to_owned()),
+                        css_id_prefix: Some("custom-prefix-".to_owned()),
+                        collapsible: true,
+                    },
+                    ..Default::default()
+                }
            ),
            AdmonitionMeta {
                directive: "note".to_owned(),
@@ -219,12 +235,14 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &AdmonitionDefaults {
-                    title: Some("Important!!!".to_owned()),
-                    css_id_prefix: Some("ignored-custom-prefix-".to_owned()),
-                    collapsible: true,
-                },
-                &CustomDirectiveMap::default(),
+                &Overrides {
+                    book: AdmonitionDefaults {
+                        title: Some("Important!!!".to_owned()),
+                        css_id_prefix: Some("ignored-custom-prefix-".to_owned()),
+                        collapsible: true,
+                    },
+                    ..Default::default()
+                }
            ),
            AdmonitionMeta {
                directive: "note".to_owned(),
@@ -247,12 +265,17 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &AdmonitionDefaults::default(),
-                &CustomDirectiveMap::from_configs(vec![CustomDirective {
-                    directive: "frog".to_owned(),
-                    aliases: Vec::new(),
-                    title: None,
-                }]),
+                &Overrides {
+                    custom: [CustomDirective {
+                        directive: "frog".to_owned(),
+                        aliases: Vec::new(),
+                        title: None,
+                        collapsible: None,
+                    }]
+                    .into_iter()
+                    .collect(),
+                    ..Default::default()
+                }
            ),
            AdmonitionMeta {
                directive: "frog".to_owned(),
@@ -275,12 +298,17 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &AdmonitionDefaults::default(),
-                &CustomDirectiveMap::from_configs(vec![CustomDirective {
-                    directive: "frog".to_owned(),
-                    aliases: Vec::new(),
-                    title: Some("🏳️‍🌈".to_owned()),
-                }]),
+                &Overrides {
+                    custom: [CustomDirective {
+                        directive: "frog".to_owned(),
+                        aliases: Vec::new(),
+                        title: Some("🏳️‍🌈".to_owned()),
+                        collapsible: None,
+                    }]
+                    .into_iter()
+                    .collect(),
+                    ..Default::default()
+                }
            ),
            AdmonitionMeta {
                directive: "frog".to_owned(),
@@ -303,12 +331,17 @@ mod test {
                    additional_classnames: Vec::new(),
                    collapsible: None,
                },
-                &AdmonitionDefaults::default(),
-                &CustomDirectiveMap::from_configs(vec![CustomDirective {
-                    directive: "frog".to_owned(),
-                    aliases: vec!["newt".to_owned(), "toad".to_owned()],
-                    title: Some("🏳️‍🌈".to_owned()),
-                }]),
+                &Overrides {
+                    custom: [CustomDirective {
+                        directive: "frog".to_owned(),
+                        aliases: vec!["newt".to_owned(), "toad".to_owned()],
+                        title: Some("🏳️‍🌈".to_owned()),
+                        collapsible: None,
+                    }]
+                    .into_iter()
+                    .collect(),
+                    ..Default::default()
+                }
            ),
            AdmonitionMeta {
                directive: "frog".to_owned(),
@@ -319,4 +352,109 @@ mod test {
            }
        );
    }
+
+    #[test]
+    fn test_admonition_info_from_raw_with_collapsible_custom_directive() {
+        assert_eq!(
+            AdmonitionMeta::resolve(
+                InstanceConfig {
+                    directive: "frog".to_owned(),
+                    title: None,
+                    id: None,
+                    additional_classnames: Vec::new(),
+                    collapsible: None,
+                },
+                &Overrides {
+                    custom: [CustomDirective {
+                        directive: "frog".to_owned(),
+                        aliases: Vec::new(),
+                        title: None,
+                        collapsible: Some(true),
+                    }]
+                    .into_iter()
+                    .collect(),
+                    ..Default::default()
+                }
+            ),
+            AdmonitionMeta {
+                directive: "frog".to_owned(),
+                title: "Frog".to_owned(),
+                css_id: CssId::Prefix("admonition-".to_owned()),
+                additional_classnames: Vec::new(),
+                collapsible: true,
+            }
+        );
+    }
+
+    #[test]
+    fn test_admonition_info_from_raw_with_collapsible_builtin_directive() {
+        assert_eq!(
+            AdmonitionMeta::resolve(
+                InstanceConfig {
+                    directive: "abstract".to_owned(),
+                    title: None,
+                    id: None,
+                    additional_classnames: Vec::new(),
+                    collapsible: None,
+                },
+                &Overrides {
+                    book: AdmonitionDefaults {
+                        title: None,
+                        css_id_prefix: None,
+                        collapsible: false,
+                    },
+                    builtin: HashMap::from([(
+                        BuiltinDirective::Abstract,
+                        BuiltinDirectiveConfig {
+                            collapsible: Some(true),
+                        }
+                    )]),
+                    ..Default::default()
+                }
+            ),
+            AdmonitionMeta {
+                directive: "abstract".to_owned(),
+                title: "Abstract".to_owned(),
+                css_id: CssId::Prefix("admonition-".to_owned()),
+                additional_classnames: Vec::new(),
+                collapsible: true,
+            }
+        );
+    }
+
+    #[test]
+    fn test_admonition_info_from_raw_with_non_collapsible_builtin_directive() {
+        assert_eq!(
+            AdmonitionMeta::resolve(
+                InstanceConfig {
+                    directive: "abstract".to_owned(),
+                    title: None,
+                    id: None,
+                    additional_classnames: Vec::new(),
+                    collapsible: None,
+                },
+                &Overrides {
+                    book: AdmonitionDefaults {
+                        title: None,
+                        css_id_prefix: None,
+                        collapsible: true,
+                    },
+                    builtin: HashMap::from([(
+                        BuiltinDirective::Abstract,
+                        BuiltinDirectiveConfig {
+                            collapsible: Some(false),
+                        }
+                    )]),
+                    ..Default::default()
+                }
+            ),
+            AdmonitionMeta {
+                directive: "abstract".to_owned(),
+                title: "Abstract".to_owned(),
+                css_id: CssId::Prefix("admonition-".to_owned()),
+                additional_classnames: Vec::new(),
+                collapsible: false,
+            }
+        );
+    }
 }
--- a/src/types.rs
+++ b/src/types.rs
@@ -5,7 +5,6 @@ use std::str::FromStr;

 /// Book wide defaults that may be provided by the user.
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize, Default)]
-#[serde(rename_all = "kebab-case")]
 pub(crate) struct AdmonitionDefaults {
    #[serde(default)]
    pub(crate) title: Option<String>,
@@ -14,6 +13,9 @@ pub(crate) struct AdmonitionDefaults {
    pub(crate) collapsible: bool,

    #[serde(default)]
+    // For backwards compatibility, we support this field with kebab-case style
+    // naming, even though this was introduced in error.
+    #[serde(alias = "css-id-prefix")]
    pub(crate) css_id_prefix: Option<String>,
 }

@@ -22,7 +24,8 @@ pub(crate) struct AdmonitionDefaults {
 /// These are guaranteed to have valid CSS/icons available.
 ///
 /// Custom directives can also be added via the book.toml config.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone, Copy, Eq, Deserialize, Serialize, Hash)]
+#[serde(rename_all = "lowercase")]
 pub(crate) enum BuiltinDirective {
    Note,
    Abstract,
@@ -83,25 +86,27 @@ impl fmt::Display for BuiltinDirective {
 /// The subset of information we care about during plugin runtime for custom directives.
 ///
 /// This drops information only needed during CSS generation.
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub(crate) struct CustomDirective {
    pub directive: String,
    pub aliases: Vec<String>,
    pub title: Option<String>,
+    pub collapsible: Option<bool>,
 }

-impl From<crate::book_config::CustomDirective> for CustomDirective {
-    fn from(other: crate::book_config::CustomDirective) -> Self {
+impl From<(String, crate::book_config::CustomDirective)> for CustomDirective {
+    fn from((directive, config): (String, crate::book_config::CustomDirective)) -> Self {
        let crate::book_config::CustomDirective {
-            directive,
            aliases,
            title,
+            collapsible,
            ..
-        } = other;
+        } = config;
        Self {
            directive,
            aliases,
            title,
+            collapsible,
        }
    }
 }
@@ -112,7 +117,7 @@ impl From<crate::book_config::CustomDirective> for CustomDirective {
 /// and returns the output-directive config.
 ///
 /// i.e. this is the step alias mapping happens at
-#[derive(Default)]
+#[derive(Debug, Clone, Default)]
 pub(crate) struct CustomDirectiveMap {
    inner: HashMap<String, CustomDirective>,
 }
@@ -121,19 +126,18 @@ impl CustomDirectiveMap {
    pub fn get(&self, key: &str) -> Option<&CustomDirective> {
        self.inner.get(key)
    }
+}

-    pub fn from_configs<T>(configs: T) -> Self
-    where
-        T: IntoIterator<Item = CustomDirective>,
-    {
+impl FromIterator<CustomDirective> for CustomDirectiveMap {
+    fn from_iter<I: IntoIterator<Item = CustomDirective>>(iter: I) -> Self {
        let mut inner = HashMap::default();
-        for directive in configs.into_iter() {
+        for config in iter.into_iter() {
            inner
-                .entry(directive.directive.clone())
-                .or_insert(directive.clone());
+                .entry(config.directive.clone())
+                .or_insert(config.clone());

-            for alias in directive.aliases.iter() {
-                inner.entry(alias.clone()).or_insert(directive.clone());
+            for alias in config.aliases.iter() {
+                inner.entry(alias.clone()).or_insert(config.clone());
            }
        }

@@ -141,6 +145,13 @@ impl CustomDirectiveMap {
    }
 }

+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+pub(crate) struct BuiltinDirectiveConfig {
+    /// Default collapsible value.
+    #[serde(default)]
+    pub collapsible: Option<bool>,
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) enum RenderTextMode {
    Strip,
@@ -158,3 +169,10 @@ pub(crate) enum CssId {
    /// will generate the rest of the id based on the title
    Prefix(String),
 }
+
+#[derive(Debug, Clone, Default)]
+pub(crate) struct Overrides {
+    pub book: AdmonitionDefaults,
+    pub builtin: HashMap<BuiltinDirective, BuiltinDirectiveConfig>,
+    pub custom: CustomDirectiveMap,
+}
--- a/v2.md
+++ b/v2.md
@@ -0,0 +1,13 @@
+# v2 Notes
+
+## Compatibility to drop
+
+- v1 config loading system from block info strings
+- v2 config loading system from block info strings
+- Support for `custom` configuration, moved to `directive.custom`
+- `css-id-prefix` kebab case
+
+## Wishlist
+
+- `mdbook` not to use a broken version of `toml` in the public api
+- `mdbook` to support loading css files from plugins
Author	SHA1	Message	Date
Tom Milligan	ea6c0a687a	Merge pull request #229 from tommilligan/prep-1.20.0 chore: prep v1.20.0 release	2025-06-06 14:53:02 +01:00
Tom Milligan	50b9187ee5	chore: prep v1.20.0 release	2025-06-06 14:35:51 +01:00
Tom Milligan	fbd07ecaf0	Merge pull request #228 from tommilligan/print-collapsed-details feat: show collapsed content in print view	2025-06-06 14:21:49 +01:00
Tom Milligan	37d03b872e	feat: show collapsed content in print view	2025-06-06 12:58:11 +01:00
Tom Milligan	fa91fe3778	Merge pull request #227 from tommilligan/update-deps-2025-06 chore: update dependencies	2025-06-06 12:37:47 +01:00
Tom Milligan	d59dce3533	chore: update dependencies	2025-06-06 12:34:38 +01:00
Tom Milligan	21d86546ff	Merge pull request #224 from tommilligan/fix-nested-list-content-indent fix: do not double indent content in lists	2025-02-17 15:55:07 +00:00
Tom Milligan	79ee592f56	chore: prep v1.19.0 release	2025-02-17 15:42:27 +00:00
Tom Milligan	0d3eb11a2c	fix: do not double indent content in lists	2025-02-17 15:38:33 +00:00
CoralPink	43579f902b	Hide extra markers displayed in `Safari`. (#185 ) * Hide extra markers displayed in `Safari`. * [review] move webkit fix --------- Co-authored-by: Tom Milligan <tom.milligan@uipath.com>	2024-08-17 06:19:01 +01:00
Tom Milligan	7ee3643dc3	Merge pull request #209 from tommilligan/deps-upgrade-2 chore: relax action constraints	2024-08-16 08:54:37 +01:00
Tom Milligan	c4bf2608e7	chore: relax action constraints	2024-08-16 08:50:25 +01:00
Tom Milligan	d4667a5f55	Merge pull request #208 from tommilligan/deps-upgrade chore: upgrade rust, deps and actions	2024-08-16 08:39:23 +01:00
Tom Milligan	8751b3cd24	chore: upgrade github actions	2024-08-16 07:56:14 +01:00
Tom Milligan	516bbc6e7e	chore: update rust lockfile	2024-08-16 07:48:11 +01:00
Tom Milligan	fc5c5eae39	chore: bump msrvc to 1.76.0	2024-08-16 07:46:50 +01:00
Tom Milligan	147a9bdb98	Merge pull request #199 from tommilligan/prep-1.18.0 chore: prep 1.18.0 release	2024-06-20 15:26:16 +01:00
Tom Milligan	540ea8e5e8	chore: prep 1.18.0 release	2024-06-20 14:43:12 +01:00
Tom Milligan	ae4bac21ba	Merge pull request #198 from tommilligan/upgrade-deps chore: upgrade deps	2024-06-20 10:53:11 +01:00
Tom Milligan	f0c4d3764e	chore: upgrade deps	2024-06-20 10:42:01 +01:00
Tom Milligan	a942a8094e	Merge pull request #197 from tommilligan/toml-serialize-error fix: use up to date toml for serialization	2024-06-20 10:40:44 +01:00
Tom Milligan	d10a427b0f	fix: use up to date toml for serialization	2024-06-20 10:05:48 +01:00
Tom Milligan	41a3b05094	Merge pull request #195 from tommilligan/aria-labelledby feat: add aria attributes to block	2024-06-15 19:51:45 +01:00
Tom Milligan	d0f73baa3f	Merge pull request #194 from tommilligan/readme-examples readme: add more example projects	2024-06-15 13:46:16 +01:00
Tom Milligan	4c40418090	feat: add aria attributes to block	2024-06-15 13:43:58 +01:00
toastal	30c9ad2269	internal: refactor html rendering	2024-06-15 13:42:38 +01:00
Tom Milligan	f7482415a7	readme: add more example projects	2024-06-15 10:20:37 +01:00
Tom Milligan	08397fbffa	Merge pull request #192 from tommilligan/prep-v1.17.1 chore: prep v1.17.1 release	2024-06-11 14:51:18 +01:00
Tom Milligan	b78fc39031	chore: prep v1.17.1 release	2024-06-11 14:14:48 +01:00
Tom Milligan	fe7b475753	Merge pull request #186 from tommilligan/tommilligan-patch-1 fix: remove stray debug statement	2024-05-29 19:54:24 +01:00
Tom Milligan	a56976d085	fix: remove stray debug statement	2024-05-29 19:48:54 +01:00
Tom Milligan	08967d550d	ci: fix deploy.yml	2024-05-24 15:06:58 +01:00
Tom Milligan	8fa1411095	Merge pull request #184 from tommilligan/fix-cargo-target-dir-release ci: be more limited with CARGO_TARGET_DIR	2024-05-24 15:05:19 +01:00
Tom Milligan	a1e5cfa48d	ci: be more limited with CARGO_TARGET_DIR	2024-05-24 14:59:46 +01:00
Tom Milligan	33fd522d68	Revert "ci: fix deploy artefacts" This reverts commit `c681ff922d`.	2024-05-24 14:50:55 +01:00
Tom Milligan	4805398359	Merge pull request #183 from tommilligan/fix-deploy-artefacts ci: fix deploy artefacts	2024-05-24 14:47:06 +01:00
Tom Milligan	c681ff922d	ci: fix deploy artefacts	2024-05-24 14:46:52 +01:00
Tom Milligan	cd0726aaf2	Merge pull request #182 from tommilligan/prep-1.17.0 chore: bump version to 1.17.0, update ci	2024-05-24 13:37:20 +01:00
Tom Milligan	a08967e073	chore: remove deprecated set-output command	2024-05-24 13:27:29 +01:00
Tom Milligan	f7e6970fa3	chore: upgrade github actions	2024-05-24 13:22:51 +01:00
Tom Milligan	5d2124b319	chore: bump version to 1.17.0	2024-05-24 13:17:20 +01:00
Tom Milligan	d79ebb4fad	chore: update v2 wishlist	2024-05-24 13:16:12 +01:00
Tom Milligan	9df896cd77	Merge pull request #181 from tommilligan/fix-breaking-on-equals-in-value fix: support toml values with equal sign	2024-05-24 13:04:16 +01:00
Tom Milligan	ffb819c315	fix: support toml values with equal sign	2024-05-24 12:59:59 +01:00
Tom Milligan	f278374c88	Merge pull request #180 from tommilligan/better-errors-for-html fix: better errors on toml parsing failures	2024-05-24 11:01:48 +01:00
Tom Milligan	2c18292401	fix: better errors on toml parsing failures	2024-05-24 10:38:39 +01:00
Tom Milligan	294af2478c	Merge pull request #177 from tommilligan/cache-ci-more ci: cache more cargo target dir	2024-05-19 17:38:27 +01:00
Tom Milligan	278d17792b	Merge pull request #178 from tommilligan/fix-changelog chore: fix changelog	2024-05-19 17:33:39 +01:00
Tom Milligan	9f6c73091a	chore: fix changelog	2024-05-19 17:33:24 +01:00
Tom Milligan	9f221abc12	ci: cache more cargo target dir	2024-05-19 17:30:47 +01:00
Tom Milligan	82c7bd4fd9	Merge pull request #176 from tommilligan/prep-1.16.0 chore: prep 1.16.0 release	2024-05-19 17:20:49 +01:00
Tom Milligan	9bca2a66df	chore: prep 1.16.0 release	2024-05-19 17:13:16 +01:00
Tom Milligan	80cce8480c	Merge pull request #174 from yannickseurin/custom-collapsible Allow to set the collapsible property for each directive	2024-05-19 17:03:37 +01:00
Yannick Seurin	5d5b73ded6	allow to set collapsible default value for each directive	2024-05-19 16:57:21 +01:00
Tom Milligan	c17a66440c	Merge pull request #175 from tommilligan/update-toml chore: dependency and msrv upgrades	2024-05-19 11:21:54 +01:00
Tom Milligan	068a375647	chore: dependency and msrv upgrades	2024-05-19 11:05:09 +01:00
Tom Milligan	f04016d017	Merge pull request #173 from yannickseurin/snake-case remove serde kebab-case renaming for AdmonitionDefaults struct	2024-05-19 09:49:38 +01:00
Tom Milligan	3f8bf86ac3	fix: allow css_id_prefix kebab cases for backcompat	2024-05-19 09:43:48 +01:00
Yannick Seurin	8045e217c9	remove serde kebab-case renaming	2024-04-29 22:53:11 +02:00
Tom Milligan	85fde44c09	Merge pull request #170 from meator/git-repository-url book: Add GitHub link	2024-03-20 11:41:40 +00:00
meator	a2c3e49ef9	book: Add GitHub link	2024-03-19 21:41:02 +01:00
Tom Milligan	8a0ecc5dd1	Merge pull request #167 from tommilligan/prep-1.15.0 chore: prep v1.15.0 release	2023-12-30 21:41:13 +01:00
@@ -1 +1 @@
 .0.2
 .1.0