rel="service-doc" Explained
The service-doc relation can expose machine-readable documentation through HTTP headers.
rel="service-doc" is a Link relation that can point clients to documentation or guidance resources for a service or website.
Using rel="service-doc" in Link headers can help crawlers discover llms.txt, documentation, or AI guidance resources earlier in the fetch process.
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Main Explanation
HTTP Link headers are sent before the HTML body is parsed. That makes them useful for discovery infrastructure.
For AI-focused websites, service-doc can point to llms.txt or related documentation.
Why this matters for AI search
rel="service-doc" Explained matters because AI systems do not only look for keywords. They need accessible pages, clear explanations, stable source URLs, and passages that answer user intent directly.
When your content is easier to crawl and easier to summarize, it may become a better source candidate for answer engines and AI assistants.
Common mistakes to avoid
- Writing long introductions before answering the actual question.
- Hiding important content behind scripts, tabs, or gated UI.
- Publishing technical files once and never maintaining them.
- Using vague headings that do not match user questions.
- Forgetting internal links to related AI visibility topics.
Practical Steps
- Choose a public documentation URL.
- Add a Link header with rel="service-doc".
- Include the correct content type.
- Test with curl -I.
Practical example
A strong AI-ready page usually starts with a direct answer, then explains the context, then lists practical steps, examples, and related resources. This makes the page useful for humans while also giving AI systems cleaner passages to extract.
For example, if a page explains an optimization concept, it should define the concept, explain why it matters, show how to test it, describe common mistakes, and link to related implementation pages.
Recommended page structure
- Start with one clear H1 that matches the topic.
- Add a Quick Answer section near the top.
- Use an AI Summary section for concise machine-readable context.
- Break instructions into short steps and examples.
- Add FAQ questions that reflect real search and AI assistant prompts.
- Link to related pages so crawlers can understand the content cluster.
FAQ
Is service-doc required?
No. It is an optional discovery signal.
Can it point to llms.txt?
Yes, if that is your service documentation resource.
How do I test it?
Run curl -I https://example.com and inspect Link headers.