elements must be contained in a

or

All list items (li) must have ul or ol parent elements.

To be considered valid, a list must have both parent and child entries. Element parents may consist of either a set of ul or ol tags. Within these tags, child elements must be declared using the li tag.

Screen readers alert users when they arrive at a list and inform them of its length. Announcing the number of items in a list and the current item helps listeners understand what they are hearing and what to anticipate as they continue to listen.

If you do not mark up a list with the correct semantic markup in a hierarchy, list elements cannot alert the listener that they are listening to a list if no parent indicates the presence of a list and its type.

What this Accessibility Rule Checks

Ensures li elements are used in a semantic way.

Learn more:

Deque Reference

Deque University - How To Fix

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W3C Reference

WCAG 2.1 - Using ol, ul and dl for lists or groups of links

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