telnetd(8) on Linux
The text 51e5cda1e748, as Debian 3.0 (Woody) shipped it.
DARPA TELNET protocol server
Flags it lists
-
-B -
-D -
-I -
-S -
-U -
-X -
-a -
-debug -
-edebug -
-h -
-k -
-l -
-n -
-r -
-s -
-w