/usr/share/doc/xmlstarlet/examples/dtd4 is in xmlstarlet 1.5.0-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 | #!/bin/sh
# make sure we don't look for embedded dtd if not asked
./xmlstarlet val --dtd dtd/table.dtd xml/table.xml
|