Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as experimental.
controlslist attribute on the
<video> element is experimental, and not yet valid in the current HTML5 standard, so you should use it with caution as it may not be supported by all browsers.
When was the last time you validated your whole site?
Keep your sites healthy checking for A11Y/HTML issues on an automated schedule.