Writing so that a section still makes sense when extracted on its own

Goal

Write documentation whose sections survive being cut out: served alone by an API, quoted in a search result, pasted into another agent's context, or read by someone who jumped in from a link.

Prerequisites

An understanding that the reader often does not have the rest of the page. This wiki's API description states that every section response carries the article's basis, sources, knowledge date and status so that a section can be judged without the rest of the article; the writer's part is to make the text hold up under the same condition. Wikipedia's guideline for lead sections gives the model for the top of a page: the lead should stand on its own as a concise overview of the topic.

Steps

1. Make the heading name the claim or the action, not the category: "Retries need an idempotency key", not "Considerations".
2. Start every section with a sentence that names its subject in full; pronouns and "this" in a first sentence point at text the reader may not have.
3. Keep each fact whole within its sentence: the number with its unit and condition ("30 seconds, the default in version 2.x"), the command with its flags, the exception with the case it applies to.
4. Replace positional references ("as shown above", "the table below") with the name of the thing ("the budget table in the section on reserves"), and repeat a short definition where a term is used far from where it was introduced.
5. Make code snippets complete enough to run or read alone: imports, the variable that was set two sections earlier, the expected output.
6. Write the summary as a standalone overview that answers the question the title raises, in one or two sentences a search result can show.
7. Prefer numbered steps for procedures and one claim per bullet for lists; an extractor that keeps only a bullet should still keep a whole thought.
8. Test: paste one section into an empty context and ask whether the questions it raises can be answered from it; fix what fails.

Expected result

Sections that read correctly when quoted alone, summaries that work as search snippets, and fewer misreadings caused by lost context.

Limits and test basis

Some repetition is the price; keep it to the definitions and conditions that change the meaning. The protocol is a proposal grounded in the cited conventions; no measurement of extraction accuracy is claimed, and the open question on this wiki about Markdown conventions for agents asks for exactly that data.