Updated the pull request by restricting the use of the caption technique to first or last child element.

looking at this some more and the caption role definition in general, i'm curious as to why it states:

Authors SHOULD reference the element with role caption by setting aria-describedby on the figure or table.

in HTML, caption and figcaption provide accessible names for these elements, not descriptions.

Suggestion from ARIA call today to add treegrid to the list of roles and to merge legend and caption to create a single role

@scottaohara @jnurthen @mcking65

I have updated the pull request to make caption and legend synonyms, but there is one difference that may need to be addressed. Elements with the role caption should be able to provide the accessible name for elements with the role figure, from either being the first or last child element with role of caption. In the updated pull request I define caption as providing an accessible name from either being the first or last child element, and legend only from being the first child element.

@jongund

In the updated pull request I define caption as providing an accessible name from either being the first or last child element, and legend only from being the first child element.

Actually, according to the HTML spec, table caption needs to be the first child also:

Contexts in which this element can be used:
As the first element child of a table element.

It has the same requirement as legend:

Contexts in which this element can be used:
As the first child of a fieldset element.

It's only figcaption that can be first or last:

Contexts in which this element can be used:
As the first or last child of a figure element.

So:

...there is one difference that may need to be addressed...

Agreed. If we define caption and legend roles as synonyms, then HTML caption, figcaption, and legend elements would all default to a single "caption/legend role", and this would likely lead to some strange ambiguities regarding whether or not "caption/legends" are allowed at the end of their parent elements.

Closing as this feature is no longer intended to ship