dtdview(1) on Linux
The text 53b9777976bf, as Debian 5.0 (Lenny), Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it. The page shows this text now.
interactively study an SGML Document Type Definition (DTD)
Flags it lists
-
-catalog -
-help -
-verbose