squid3(8) on Linux
The text be987e694cf4, as Debian 8 (Jessie) shipped it.
HTTP web proxy caching server
Flags it lists
-
-C -
-F -
-N -
-O -
-R -
-S -
-X -
-Y -
-a -
-d -
-f -
-h -
-i -
-l -
-n -
-r -
-s -
-u -
-v -
-z