a11y/no-duplicate-dt · Duplicate <dt> names in a <dl>

Within a single dl element there should not be more than one dt element for each name; a duplicated term usually means two descriptions were meant to share one dt.

Severity: info · Category: a11y

What it checks

Flags a <dt> whose text duplicates an earlier <dt> in the same <dl>:

<dl>
  <dt>Coffee</dt>
  <dd>Hot, brewed</dd>
  <dt>Coffee</dt>
  <dd>Iced, cold brew</dd>
</dl>

A term’s name is its static text content, and static phrasing markup is looked through, so <dt><code>HTTP</code></dt> and <dt>HTTP</dt> carry the same name, and comments contribute nothing. Names are compared after trimming and collapsing internal whitespace, case-sensitively (the spec leaves the equality unstated, so only certain duplicates are reported). The div-wrapped name-value-group form counts too: a <dt> that is a direct child of a <div> directly inside the <dl> participates. Each <dl> is its own scope. The same term in two different lists is fine, and a <dl> nested inside a <dd> is judged on its own.

Not flagged:

A <dt> with any dynamic content. An {expression}, component, block, or custom-element child anywhere below makes the name unknowable.
A <dt> under a logic block ({#if}, {#each}, …) or inside a component, whose multiplicity or rendered content is unknowable.
Empty or whitespace-only <dt>s. Two blank terms are a missing-content defect, not a duplicate name.
A <dl> inside <svg>, which never renders as an HTML description list.

Why it matters

The HTML spec states that within a single dl element, there should not be more than one dt element for each name. In practice a duplicated term is almost always a copy-paste error: two descriptions were meant to share one term, since a single <dt> may be followed by several <dd> elements.

How to fix

Merge the descriptions under one <dt>:

<dl>
  <dt>Coffee</dt>
  <dd>Hot, brewed</dd>
  <dd>Iced, cold brew</dd>
</dl>

Or rename one of the terms if the entries are genuinely different.

Mode differences

None. This rule reads source, the same .svelte and .ts files, everywhere it runs. The CLI, the Vite plugin’s build pass, and the live dashboard’s static baseline all report it identically, and the rendered-HTML pass never re-evaluates it. Scoping a run with --route skips it: component-scoped rules have no route to attribute a finding to.

Disabling

If the duplicate is intended, silence the element with , or turn the rule off:

export default {
  rules: {
    'a11y/no-duplicate-dt': 'off'
  }
};