RFC 2119 keywords and XML tag structure guide for agent prompts, skill definitions, and internal documentation.
Use when writing, reviewing, or refactoring markdown files that instruct AI agents — including skills, prompt templates,
system prompts, and workflow docs. Provides keyword semantics, XML tag catalog, nesting best practices, and before/after examples.
Examples:
- user: "Refactor this skill to use RFC keywords" → apply RFC 2119 keyword conventions
- user: "Add XML structure to this prompt" → wrap sections in semantic XML tags
- user: "Review my SKILL.md formatting" → audit RFC keyword usage and XML structure
- user: "Convert this doc to RFC+XML style" → full transformation with style guide
- user: "/refactor-rfc-xml ./prompts" → batch refactor all markdown in a folder
Installation
Installer avec Codex ou Claude Copiez ce prompt, collez-le dans Codex, Claude ou un autre assistant, puis laissez-le vérifier la page du skill et l'installer pour vous.
RFC 2119 keywords and XML tag structure guide for agent prompts, skill definitions, and internal documentation.
Use when writing, reviewing, or refactoring markdown files that instruct AI agents — including skills, prompt templates,
system prompts, and workflow docs. Provides keyword semantics, XML tag catalog, nesting best practices, and before/after examples.
Examples:
- user: "Refactor this skill to use RFC keywords" → apply RFC 2119 keyword conventions
- user: "Add XML structure to this prompt" → wrap sections in semantic XML tags
- user: "Review my SKILL.md formatting" → audit RFC keyword usage and XML structure
- user: "Convert this doc to RFC+XML style" → full transformation with style guide
- user: "/refactor-rfc-xml ./prompts" → batch refactor all markdown in a folder
Authoritative reference for structuring agent-facing documentation with RFC 2119 requirement-level keywords and semantic XML tags. Covers keyword definitions, XML tag catalog, naming conventions, nesting rules, and combined usage patterns.
RFC/XML is for STRUCTURE, not COMMUNICATION
RFC 2119 keywords and XML tags are for structuring agent prompts, skill definitions, and internal documentation ONLY.
Files MUST NOT be modified such that agents would:
Speak to users using RFC keywords ("You MUST provide a file path")
Output XML tags in their responses to users
Adopt a formal/robotic communication style
Refactored files SHOULD make agents BEHAVE correctly, not SPEAK formally.
NO RFC Boilerplate
You MUST NOT add any RFC 2119 preamble or boilerplate text to files. Models already know what RFC keywords mean. Adding a preamble wastes tokens and clutters the file.
Read the full style guide reference before applying any transformations:
Style Guide: references/style-guide.md — RFC 2119 keyword definitions, XML tag catalog, naming conventions, nesting rules, and combined patterns
Applying RFC+XML to a file
Read the file and identify its type (skill, prompt template, system prompt, workflow doc)
Identify sections that map to XML tags (instructions, workflows, examples, constraints, etc.)
Identify requirement-level language that SHOULD use RFC keywords
Apply XML tags to wrap logical sections — use consistent naming, max 3-4 nesting levels
Apply RFC 2119 keywords — convert casual requirement language to proper keywords
Preserve YAML frontmatter, code blocks, links, and original intent exactly as-is
Verify XML is well-formed (proper nesting, all tags closed)
Verify RFC keywords are used appropriately (not overused, not in user-facing output)
XML is well-formed (proper nesting, all tags closed)
RFC keywords used appropriately (not overused)
Frontmatter preserved exactly
Code blocks and their content untouched
Files remain readable and clear
Tags enhance structure, don't obscure content
NO RFC/XML leakage into agent communication style
Agents still speak naturally to users
Internal instruction: "The agent MUST verify file exists before editing"
User-facing output: "I MUST inform you that the file does not exist"
Internal structure: `1. Check permissions 2. Edit file`
User-facing output: `File has been edited`
