Assistive technology users should be able to detect when important changes occur on a web page, With the use of a status message, information can be provided to the user without changing focus or unnecessarily interrupting their work.
Effectively and accessibly communicate form errors by: Communicating that a form has errors, Communicating any individual errors case by case, including clear guidance on how to address the error.
For a number of reasons including data persistence, performance and security, it is sometimes beneficial to terminate idle user sessions. It's important to warn people a session is about to expire and give them the option to continue.
Providing form feedback accessibly helps users submit data more accurately and reduces the chance for error.