markdown-accessibility

# Markdown Accessibility Skill Reusable knowledge module for the `markdown-a11y-assistant`, `markdown-scanner`, and `markdown-fixer` agents and the `markdown-accessibility` always-on instructions. Provides pattern libraries, severity scoring, fix templates, emoji translation maps, diagram description templates, and GitHub anchor generation rules for comprehensive markdown accessibility auditing across 9 domains. ## Domains Covered 1. **Descriptive Links** (WCAG 2.4.4) - Ambiguous link text, bare URLs, repeated identical text 2. **Image Alt Text** (WCAG 1.1.1) - Missing, empty, filename-as-alt, generic placeholders 3. **Heading Hierarchy** (WCAG 1.3.1 / 2.4.6) - Skipped levels, multiple H1s, bold-as-heading 4. **Table Accessibility** (WCAG 1.3.1) - Missing descriptions, empty headers, layout tables 5. **Emoji** (WCAG 1.3.3 / Cognitive) - Remove-all, remove-decorative, translate, or leave-unchanged modes 6. **Mermaid and ASCII Diagrams** (WCAG 1.1.1 / 1.3.1) - Replace with accessible text + collapsible source 7. **Em-Dash / En-Dash Normalization** (Cognitive) - Normalize to ` - ` or leave unchanged 8. **Anchor Link Validation** (WCAG 2.4.4) - Validate `#anchor` links against actual headings 9. **Plain Language and List Structure** (Cognitive) - Emoji bullets, passive voice, sentence length ## Severity Scoring | Issue | Severity | WCAG | Auto-fix? | |-------|----------|------|-----------| | Image missing alt text | Critical | 1.1.1 (A) | No - needs visual judgment | | Mermaid diagram with no text alternative | Critical | 1.1.1 (A) | Partial - simple diagrams auto-described; complex need human | | ASCII diagram with no text description | Critical | 1.1.1 (A) | Partial - flag and wrap; description needs human or auto-gen | | Broken anchor link | Serious | 2.4.4 (A) | No - confirm which end changes | | Ambiguous link text ("here", "click here") | Serious | 2.4.4 (A) | Yes - rewrite using surrounding context | | Skipped heading level | Serious | 1.3.1 (A) | Yes - interpolate missing level | | Multiple H1s | Serious | 1.3.1 (A) | Yes - demote all but first | | Emoji in heading | Moderate | Cognitive | Yes - remove or translate per preference | | Consecutive emoji (2+) | Moderate | 1.3.3 (A) | Yes - remove sequence or translate | | Emoji used as bullet | Moderate | 1.3.1 (A) | Yes - replace with `-` | | Em-dash in prose | Moderate | Cognitive | Yes - replace with ` - ` | | Table without preceding description | Moderate | 1.3.1 (A) | Yes - add one-sentence summary | | Bold text used as heading | Minor | 2.4.6 (AA) | Yes - convert to appropriate heading | | Bare URL in prose | Minor | 2.4.4 (A) | Yes - wrap with descriptive text | | Emoji used for meaning, single inline | Minor | 1.3.3 (A) | Conditional - remove-all: yes; remove-decorative: flag; translate: translate | ### Scoring Formula ```text File Score = 100 - (sum of weighted findings) Critical: -15 pts each Serious: - 7 pts each Moderate: - 3 pts each Minor: - 1 pt each Floor: 0 ``` ### Score Grades | Score | Grade | Meaning | |-------|-------|---------| | 90-100 | A | Excellent - accessible documentation | | 75-89 | B | Good - minor issues | | 50-74 | C | Needs Work - several barriers | | 25-49 | D | Poor - significant barriers | | 0-24 | F | Failing - critical AT barriers | ## Emoji Handling Modes The agent supports four modes configured during Phase 0: | Mode | Description | Default? | |------|-------------|----------| | `remove-all` | Strip every emoji from prose, headings, and bullets | No | | `remove-decorative` | Remove emoji in headings, bullets, and consecutive sequences; flag single inline for review | **Yes (default)** | | `translate` | Replace known emoji with `(English)` text; flag unknown for review | No | | `leave-unchanged` | Do not flag or modify any emoji | No | ### Emoji Translation Map When using `translate` mode, replace each emoji with the parenthesized English equivalent: | Emoji | Translation | Emoji | Translation | |-------|------------|-------|------------| | 🚀 | (Launch) | ✅ | (Done) | | ⚠️ | (Warning) | ❌ | (Error) | | 📝 | (Note) | 💡 | (Tip) | | 🔧 | (Configuration) | 📚 | (Documentation) | | 🎯 | (Goal) | ✨ | (New) | | 🔍 | (Search) | 🛠️ | (Tools) | | 👋 | (Hello) | 🎉 | (Celebration) | | ⭐ | (Featured) | 💬 | (Discussion) | | 🏠 | (Home) | 📊 | (Data) | | 🔒 | (Security) | 🌐 | (Web) | | 📦 | (Package) | 🔗 | (Link) | | 📋 | (Checklist) | 🏆 | (Achievement) | | ⚡ | (Quick) | 👍 | (Approved) | | 👎 | (Rejected) | 🐛 | (Bug) | | 🤝 | (Collaboration) | 🎓 | (Learning) | | 🔑 | (Key) | 📌 | (Pinned) | | ℹ️ | (Info) | 🔄 | (Refresh) | | ➕ | (Add) | ➖ | (Remove) | | 💻 | (Code) | 🔔 | (Notification) | | 📣 | (Announcement) | 🧪 | (Test) | | 🎨 | (Design) | 🌟 | (Highlight) | | 📈 | (Increase) | 📉 | (Decrease) | | 🏗️ | (Build) | 🔐 | (Locked) | | 📂 | (Folder) | 📁 | (Folder) | | 🗂️ | (Category) | 🗃️ | (Archive) | | ⚙️ | (Settings) | 🏁 | (Finish) | | 🚧 | (In Progress) | 🚫 | (Not Allowed) | | ✔️ | (Check) | ➡️ | (Next) | | ⬆️ | (Up) | ⬇️ | (Down) | For emoji not in this table: flag as `needs-human-review`. Do not guess. ### Emoji Detection Unicode Ranges ```text [\u{1F600}-\u{1F64F}] - Emoticons [\u{1F300}-\u{1F5FF}] - Misc symbols and pictographs [\u{1F680}-\u{1F6FF}] - Transport and map symbols [\u{1F700}-\u{1F77F}] - Alchemical symbols [\u{1F780}-\u{1F7FF}] - Geometric shapes extended [\u{1F900}-\u{1F9FF}] - Supplemental symbols [\u{1FA70}-\u{1FAFF}] - Symbols and pictographs extended [\u{2600}-\u{26FF}] - Misc symbols [\u{2700}-\u{27BF}] - Dingbats [\u{1F1E0}-\u{1F1FF}] - Flags [\u{FE00}-\u{FE0F}] - Variation selectors ``` Emoji-as-bullet pattern: list item where the first non-whitespace character is an emoji. ## Pattern Library: Mermaid and ASCII Diagrams ### Mermaid Detection Lines matching ` ```mermaid` (with optional leading spaces/tabs). ### Mermaid Description Templates | Type | Description Template | |------|---------------------| | `graph TD/LR/RL/BT` / `flowchart` | "The following [direction] diagram shows: [list major nodes and connections from source]" | | `sequenceDiagram` | "The following sequence diagram shows the interaction between [participants]: [list each message in order]" | | `classDiagram` | "The following class diagram shows [N] classes: [list class names, key properties, and relationships]" | | `erDiagram` | "The following entity-relationship diagram shows [entities] with these relationships: [list relationships]" | | `gantt` | "The following Gantt chart shows project tasks: [list section names and tasks with dates if available]" | | `pie` | "The following pie chart shows [title] with values: [list each label and percentage/value if available]" | | `stateDiagram` | "The following state diagram shows [N] states: [list state names and transition triggers]" | | `mindmap` | "The following mind map shows [root topic] with branches: [list top-level branch names]" | | `timeline` | "The following timeline shows events: [list events in chronological order]" | Auto-generate description for: `graph`, `flowchart`, `pie`, `gantt`, `mindmap`, `timeline`. Flag for human review: `sequenceDiagram`, `classDiagram`, `erDiagram`, `stateDiagram` (complex enough to need human verification). ### Mermaid Replacement Template ```markdown [Generated or user-provided text description - this is the primary accessible content] <details> <summary>Diagram source (Mermaid)</summary> ```mermaid [original diagram source - unchanged] ```text </details> ``` ### ASCII Diagram Detection ASCII art patterns: non-code-block lines (or unnamed code blocks) containing combinations of `+`, `-`, `|`, `/`, `\`, `>`, `<`, `^`, `v`, `*` forming a visual structure. Minimum 3 lines with consistent column alignment. ### ASCII Diagram Replacement Template ```markdown [Generated or user-provided text description - this is the primary accessible content] <details> <summary>ASCII diagram</summary> ``` [original ASCII art - unchanged] ```html </details> ``` ## Pattern Library: Ambiguous Link Detection Match these patterns (case-insensitive, trim whitespace): ### Exact-match violations ```text here, click here, read more, learn more, more, more info, link, details, info, go, see more, continue, start, download, view, open, submit, this, that ``` ### Starts-with violations ```text click here to ..., read more about ..., learn more about ..., here to ..., see more ... ``` ### URL-as-text pattern Any link where visible text matches `https?://` or `www\.` ### Repeated identical text Multiple `[X](url1)` and `[X](url2)` with same X but different URLs on the same page. ### Safe patterns (do not flag) - Badge links: `[](url)` at top of README - Section self-references: `[Installation](#installation)` where text matches heading - Footer resource lists using the resource/tool name as text ## Pattern Library: GitHub Anchor Generation GitHub converts headings to anchor IDs using these rules: 1. Lowercase entire string 2. Remove all characters except: letters (a-z), digits (0-9), spaces, hyphens 3. Replace spaces with hyphens 4. Remove leading and trailing hyphens ### Examples | Heading | Anchor | |---------|--------| | `# Getting Started` | `#getting-started` | | `## API: v2.0 Reference` | `#api-v20-reference` | | `### What's New?` | `#whats-new` | | `## C# and .NET Support` | `#c-and-net-support` | | `## Step 1: Installation` | `#step-1-installation` | | `## FAQ (Frequently Asked Questions)` | `#faq-frequently-asked-questions` | | `## 🚀 Quick Start` | `#-quick-start` (emoji becomes empty, may vary) | For headings containing emoji: GitHub strips the emoji character and generates an anchor from the remaining text. Anchors referencing emoji-containing headings are fragile and should be flagged. ## Pattern Library: Emoji Detection Unicode emoji ranges for regex detection: ```text [\u{1F600}-\u{1F64F}] # Emoticons [\u{1F300}-\u{1F5FF}] # Misc symbols and pictographs [\u{1F680}-\u{1F6FF}] # Transport and map symbols [\u{1F700}-\u{1F77F}] # Alchemical symbols [\u{1F780}-\u{1F7FF}] # Geometric shapes extended [\u{1F800}-\u{1F8FF}] # Supplemental arrows-C [\u{1F900}-\u{1F9FF}] # Supplemental symbols and pictographs [\u{1FA00}-\u{1FA6F}] # Chess symbols [\u{1FA70}-\u{1FAFF}] # Symbols and pictographs extended-A [\u{2600}-\u{26FF}] # Misc symbols [\u{2700}-\u{27BF}] # Dingbats [\u{FE00}-\u{FE0F}] # Variation selectors [\u{1F1E0}-\u{1F1FF}] # Flags ``` Emoji-as-bullet pattern: List item where first non-whitespace character is an emoji. ## Pattern Library: Em-Dash and En-Dash Detection patterns: ```text