/usr/share/man/de/man1/grep-available.1.gz is in dctrl-tools 2.23ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/de/man1/grep-dctrl.1.gz
/usr/share/man/de/man1/grep-dctrl.1.gz