in.telnetd(8) on Linux
The text 2a798415ffdf, as Debian 2.0 (Hamm), Debian 1.3 (Bo) shipped it.
DARPA telnet protocol server
Flags it lists
-
-D -
-L -
-S -
-X -
-a -
-edebug -
-h -
-n -
-s