/usr/share/doc/libunique-3.0-dev/AUTHORS is in libunique-3.0-dev 3.0.2-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libunique-3.0-dev/../libunique-3.0-0/AUTHORS
/usr/share/doc/libunique-3.0-dev/../libunique-3.0-0/AUTHORS