marked safe

 marked safe  is a notification feature that tells you when those you follow have marked themselves as safe in an area affected by a disaster or other physical emergency within a geographical area.

Facebook
Facebook has supported "marked safe" as a notification and as an opt-in feature for those wanting to mark themselves as safe since 2013?

2016-07-14 Screenshot of notification from the "globe icon" drop down list:



Text notification example from an actual notification seen 2015-11-13 [image of person1] Person1, Person2 and 4 others were marked safe during DisasterEventName. https://static.xx.fbcdn.net/rsrc.php/v2/yA/r/TMKWNNYEc1S.png 29 minutes ago Where
 * "Person 1" is the most recent person that has marked themselves safe, "Person 2" is the second most recent, etc.
 * "4 others" is the summary of however many other people you follow were marked safe
 * "29 minutes ago" is the time since the most recent person has marked themselves safe.
 * DisasterEventName is the name given to the disaster (apparently) by Facebook.