/usr/share/doc/debian-policy/upgrading-checklist-1.html is in debian-policy 3.9.8.0.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/debian-policy/policy.html/upgrading-checklist.html
/usr/share/doc/debian-policy/policy.html/upgrading-checklist.html