Examples adapted from http://codetalks.org/source/widgets/alert/alert.html#
Note: alerts should not get focus, but we include that in the testing to ensure screen readers don't get confused if they are, because it may be a common mistake.
Buttons to create different alerts:
Some text after the alert to help with selection in order to view alert source
Superclass Role: region
Subclass Roles: alertdialog
Related Concepts: XForms alert
Inherited States and Properties: aria-atomic, aria-busy (state), aria-controls, aria-describedby, aria-disabled (state), aria-dropeffect, aria-expanded (state) aria-flowto, aria-grabbed (state) aria-haspopup, aria-hidden (state), aria-invalid (state), aria-label, aria-labelledby, aria-live, aria-owns, aria-relevant,
Name From: author
Implicit Value for Role: Default for aria-live is assertive.