mutt(1) on Linux
The text dd3830fdfa67, as Debian 9 (Stretch) shipped it.
The Mutt Mail User Agent
Flags it lists
-
-- -
-A -
-D -
-E -
-F -
-G -
-H -
-Q -
-R -
-Z -
-b -
-c -
-d -
-e -
-f -
-g -
-h -
-i -
-m -
-n -
-p -
-s -
-v -
-vv -
-x -
-y -
-z