/usr/share/man/man1/docbook-2-rtf.1.gz is in sgml2x 1.0.0-11.4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/sgml2x.1.gz
/usr/share/man/man1/sgml2x.1.gz