/usr/share/omf/gtk-doc-manual/ is in gtk-doc-tools 1.18-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-C.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-bn_IN.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-de.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-el.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-en_GB.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-es.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-fr.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-gu.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-sl.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-sv.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-ta.omf
/usr/share/omf/gtk-doc-manual/gtk-doc-manual-te.omf