Glossary

A short glossary of the terms that show up on this site (and in AGENTS.md) when describing how AI agents read the web.

AGENTS.md

A plain-text instructions file at the root of a site — like robots.txt, but for AI agents and automated systems. Tells crawlers where to find clean content, how to identify themselves, and what to avoid. Lives at /AGENTS.md.

a14y

Short for “agent accessibility.” A scorecard and toolkit at a14y.dev that measures how well a site is structured for AI agents — separate from WCAG, which measures human accessibility. The name is a homophone, not a synonym.

The <link rel="canonical" href="…"> tag in a page’s <head>, plus the Link: <…>; rel="canonical" HTTP header. Both tell agents which URL is the “real” one when the same content is reachable at multiple paths.

content negotiation

When a server returns different versions of the same URL depending on the Accept header sent by the client. For example, returning HTML for Accept: text/html and Markdown for Accept: text/markdown at the same URL. This site does not currently use content negotiation — fetch the .md URL directly.

JSON-LD

JavaScript Object Notation for Linked Data — a way to embed structured data inside an HTML page using a <script type="application/ld+json"> block. Search engines and agents use it to extract entities (person, organization, article, breadcrumb) without parsing the visible markup.

llms.txt

A convention defined at llmstxt.org for publishing a Markdown summary of a site at /llms.txt. Optional companion /llms-full.txt carries the long version. Both live at the site root.

Markdown mirror

A .md copy of an HTML page, served at the same path with index.md (or .md) appended. Agents prefer Markdown because it strips away presentational HTML and JavaScript. Every HTML page on this site has a mirror — see the <link rel="alternate" type="text/markdown"> in <head>.

sitemap.md

A Markdown index of every page on the site, served at /sitemap.md. The Markdown counterpart of the standard /sitemap.xml. Agents that can’t parse XML use this instead.

scorecard

In a14y, a versioned collection of checks. Pinning a scorecard version makes score comparisons meaningful across audits — version 0.2.0 measures different things than 0.3.0 would.

structured data

Umbrella term for machine-readable annotations on a page — usually JSON-LD, Microdata, or RDFa. This site uses JSON-LD.