WCAG 3.1.3 — Unusual Words
Industry jargon, regional slang, technical terms with everyday surface meanings — they create entry barriers for users with cognitive disabilities and for anyone outside the niche. AAA wants a way to look them up in place.
What this requires
A mechanism is available for identifying specific definitions of
words or phrases used in an unusual or restricted way, including
idioms and jargon. The mechanism can be inline (a definition list on
the page, a <dfn> element on first use), contextual (a tooltip or
popover), or external (a glossary linked from the page).
How AI coding tools fail this
When asked to write technical documentation or marketing copy, AI tools use industry shorthand without defining it. "Serverless", "observability", "shift-left", "developer experience" — terms that mean very specific things inside the niche and roughly nothing outside it.
The second pattern: glossaries that exist as a separate page but aren't linked from where the terms appear. The reader has to know the glossary exists, leave the article, search for the term, and return.
The third: definitions hidden behind hover tooltips with no discoverable affordance. A keyboard or touch user has no way to find them.
Edge cases
- Audience expectation matters. A technical-architecture document on a tools site can use "API" without definition; a marketing landing page might not.
- Linked glossary entries are the cheapest mechanism on a docs site. Build it once, reuse everywhere.
<dfn>element marks the defining instance of a term, helping screen readers and indexes.- Idioms ("by and large", "out of pocket") are also in scope. A multilingual audience may not parse them.
- AAA target. Most projects target AA; 3.1.3 is the polish layer.
How Jeikin handles this
This is a manual editorial review. The dashboard records, per content piece, whether a glossary is linked and whether jargon is defined on first use. The scanner can extract candidate jargon terms from a lexicon and surface them for review, but the call is editorial.