WCAG 2.2 Demo Suite

3.1.3 Level AAA Guideline 3.1 Readable Added in WCAG 2.0 Not detectable automatically

Unusual Words

A mechanism is available for identifying specific definitions of words or phrases used in an unusual or restricted way, including idioms and jargon.

Who this affects

Users with cognitive and learning disabilities, for whom idioms are often read literally. Users reading in a second language. Anyone new to the domain's jargon.

The failure and the fix

Each example below is a self-contained page, loaded in a frame so its markup cannot affect this page. Open either one on its own to test it with a keyboard or screen reader.

Fails 3.1.3

Open the failing example in a new tab

fail.html — the problem

<h1>Selling your books to us</h1>

<!-- FAILURE 1: trade jargon used with no definition. "Foxing", "ex-libris"
     and "remainder mark" are precise terms in the second-hand book trade and
     meaningless to a first-time seller. -->
<p>We assess every book for foxing, ex-libris marks and remainder marks before
   making an offer.</p>

<!-- FAILURE 2: an idiom. Users with cognitive disabilities, and readers for
     whom English is a second language, frequently interpret idioms literally.
     "Ballpark figure" has no relationship to a ball or a park. -->
<p>Our buyer will give you a ballpark figure on the day, and we will not beat
   around the bush if the answer is no.</p>

<!-- FAILURE 3: a word used in a restricted, non-obvious sense. In this trade
     "condition" is a formal grading scale, not the everyday word. -->
<p>Payment depends on condition.</p>

Meets 3.1.3

Open the passing example in a new tab

pass.html — the fix

<h1>Selling your books to us</h1>

<!-- FIX 1: define jargon at or near first use, and link to a glossary entry.
     The dfn element marks the defining instance, which assistive technology
     can expose. -->
<p>We assess every book for
   <a href="#g-foxing"><dfn id="d-foxing">foxing</dfn></a>,
   <a href="#g-exlibris"><dfn id="d-exlibris">ex-libris marks</dfn></a> and
   <a href="#g-remainder"><dfn id="d-remainder">remainder marks</dfn></a>
   before making an offer.</p>

<!-- FIX 2: the idioms are gone, replaced with literal language. Rewriting is
     almost always better than explaining an idiom - the plain version is
     shorter and clearer for every reader. -->
<p>Our buyer will give you an estimated price on the day, and will tell you
   directly if we cannot make an offer.</p>

<!-- FIX 3: the restricted sense is spelled out. -->
<p>Payment depends on the book's <a href="#g-condition">condition grade</a>.</p>

<h2 id="glossary">Glossary</h2>
<dl>
  <dt id="g-foxing">Foxing</dt>
  <dd>Small brown or rust-coloured spots on old paper, caused by damp or ageing.</dd>
  <dt id="g-exlibris">Ex-libris mark</dt>
  <dd>A bookplate or stamp showing a previous owner, usually inside the front cover.</dd>
  <dt id="g-remainder">Remainder mark</dt>
  <dd>A line or dot marked on the page edges by a publisher when unsold stock is
      sold off cheaply.</dd>
  <dt id="g-condition">Condition grade</dt>
  <dd>Our five-point scale from "as new" to "reading copy", based on the state of
      the cover, spine and pages.</dd>
</dl>

<!-- Scope: 3.1.3 applies to words used in an UNUSUAL or RESTRICTED way,
     including idioms and jargon. It does not ask you to define every long
     word, and it does not apply to ordinary vocabulary.

     The best fix is usually not a glossary at all - it is writing the sentence
     without the jargon. Reach for a definition when the technical term is
     genuinely needed, which is often when the reader has to recognise it
     elsewhere. -->

How to test it

Identify jargon, idioms, and domain terms. Confirm a glossary, inline definition, or dfn element gives the meaning at or near first use.

  • Automated

    Identifying which words are unusual for the audience requires human reading.

    No axe rule maps to this criterion. It has to be checked by a person.

  • Keyboard

    Unplug the mouse. Move through the page with Tab, Shift+Tab, Enter, Space and the arrow keys. See the keyboard testing script.

  • Screen reader

    Listen to both examples with NVDA, JAWS, VoiceOver or TalkBack and compare what is announced. See the screen reader cheat sheets.

  • Visual

    Zoom to 200% and 400%, narrow the viewport to 320 px, and apply the text-spacing overrides. See the visual testing procedures.

In the specification