dtdtree(1) on Linux
The text 076f0354c55a, as Debian 5.0 (Lenny), Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it. The page shows this text now.
generate a tree view of an SGML Document Type Definition (DTD)
Flags it lists
-
-catalog -
-dtd -
-help -
-level -
-treefile -
-verbose