squid3(8) on Linux
The text 260195c286b3, as Debian 5.0 (Lenny) shipped it.
proxy caching server
Flags it lists
-
-C -
-D -
-F -
-N -
-O -
-R -
-X -
-Y -
-a -
-d -
-f -
-h -
-i -
-l -
-n -
-r -
-s -
-u -
-v -
-z