/usr/share/sgml/gtk-doc/gtk-doc.catalog is in gtk-doc-tools 1.27-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | PUBLIC "-//GtkViaAlcove//DOCUMENT Gtk-doc HTML Stylesheet//EN"
"/usr/share/gtk-doc/data/gtk-doc.dsl"
|