Contributions to this repository are intended to become part of Recommendation-track documents governed by the W3C Patent Policy and Software and Document License. To make substantive contributions to specifications, you must either participate in the relevant W3C Working Group or make a non-member patent licensing commitment.

If you are not the sole contributor to a contribution (pull request), please identify all contributors in the pull request comment.

To add a contributor (other than yourself, that's automatic), mark them one per line as follows:


If you added a contributor by mistake, you can remove them in a comment with:


If you are making a pull request on behalf of someone else but you had no part in designing the feature, you can remove yourself with the above syntax.


For normative changes for any specification in CR or later as well as the pre-CR specifications listed below, a corresponding web-platform-tests PR must be provided, except if testing is not practical; for other specifications it is usually appreciated. Typically, both PRs will be merged at the same time. Note that a test change that contradicts the spec should not be merged before the corresponding spec change. If testing is not practical, please explain why and if appropriate file an issue to follow up later. Add the type:untestable or type:missing-coverage label as appropriate.

The pre-CR specifications with this testing requirement are currently: