/usr/share/help/ro/gdm/index.docbook is in gdm3 3.28.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/help/ro/gdm/../../../help-langpack/ro/gdm/index.docbook
/usr/share/help/ro/gdm/../../../help-langpack/ro/gdm/index.docbook