Status messages should be programmatically determinable through appropriate roles or properties, allowing assistive technologies to present the information to users without altering their current focus.
When additional content becomes visible upon receiving pointer hover or keyboard focus (and subsequently becomes hidden when these triggers are removed) it should be dismissible in a manner that allows users to close the content without needing to move the pointer or re-focus. This applies unless the additional content communicates an input error (that has then been addressed) or does not obscure or replace other content.

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AccessibilityOz is an accessibility consultancy based in Australia and the United States. Gian Wild, the founder and Director, has worked in the accessibility industry since 1998 and spent six years with the W3C Web Content Accessibility Guidelines Working Group contributing to WCAG2. AccessibilityOz offers a range of accessibility services and products to organisations and Government departments around the world. We have completed hundreds of audits and run training sessions and seminars over the last ten years for clients including United Nations, National Science Foundation, Department of Prime Minister and Cabinet, Bureau of Meteorology and McDonald’s.