Where receiving and then removing pointer hover or keyboard focus triggers additional content to become visible and then hidden, the following are true:
Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author.
The purpose of this success criterion is to ensure that users can control the display of information that appears on a hover or focus event so that it does not interfere with their ability to read the content beneath.
How to Meet
When authors add content that appears on a hover or focus event, they need to ensure that each of the requirements of the success criterion are satisfied.
As digital publications are rarely designed to be read by users with pointing devices and keyboards, this success criterion is generally not applicable. The closest analogy in publications are pop-up footnotes, but these do not fall under this success criterion both because they are generated by reading systems and because they typically require a click event to appear.
The knowledge base does not currently include information on displaying content in response to hover and focus events due the lack of implementation in publishing formats. Refer to the WCAG guidance documents for additional information.