/usr/share/help/ca/fdl/index.docbook is in gnome-desktop3-data 3.8.4-0ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/help/ca/fdl/../../../help-langpack/ca/fdl/index.docbook
/usr/share/help/ca/fdl/../../../help-langpack/ca/fdl/index.docbook