The K Button is a critical feature for alert notifications:
Critical Alerts: The K expands, turns red, and shows the Alert type. It stays red for the duration of the Alert. Pressing it takes users directly to the Near me filter of the Emergencies feed.
Non-Critical Alerts: Functions similarly to Critical Alerts but the expanded K is yellow.
No Alerts: K stays grey when there are no alerts and indicates what it does when users tap on grey K button.
Back Arrow Presence: If a Back Arrow is required on a page during a Critical Alert, the expanded red K reverts to its normal size but remains red until the Back Arrow is no longer needed or the Alert expires.