lastb(1) on Linux
The text 452186bccb16, as Debian 5.0 (Lenny), Debian 4.0 (Etch) shipped it.
show listing of last logged in users
Flags it lists
-
-R -
-a -
-d -
-f -
-i -
-n -
-num -
-o -
-t -
-x