1.4.13 Content on Hover or Focus (Level AA)
This guideline states that if users trigger content in the form of a modal window, tooltip or a similar component, they must be able to:

About

  • Dismiss the content without moving the mouse cursor or the current keyboard focus (for example by pressing the Esc key).
  • Scroll to the content (thereby moving the mouse cursor) without making the content disappear (when the cursor moved).

Example:

There are two suggestions to allow this to be possible:

  1. By pressing escape on the keyboard
  2. By offering a close button