See security banner (also known as notice and consent banners)
Sources:
CNSSI 4009-2015
1. A persistent visible window on a computer monitor that displays the highest level of data accessible during the current session.
Sources:
CNSSI 4009-2015
under security banner
2. The opening screen that informs users of the implications of accessing a computer resource (e.g. consent to monitor).
Sources:
CNSSI 4009-2015
under security banner