/usr/share/doc/ is in doc-debian 4.0.2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc-base/debian-manifesto
/usr/share/doc-base/debian-reporting-bugs
/usr/share/doc-base/debian-constitution-text
/usr/share/doc-base/debian-mailing-lists
/usr/share/doc-base/debian-social-contract
/usr/share/doc/doc-debian/
/usr/share/doc/doc-debian/copyright
/usr/share/doc/doc-debian/changelog.gz
/usr/share/doc/debian/
/usr/share/doc/debian/bug-log-access.txt
/usr/share/doc/debian/bug-log-mailserver.txt
/usr/share/doc/debian/bug-mailserver-refcard.txt
/usr/share/doc/debian/bug-maint-info.txt
/usr/share/doc/debian/bug-maint-mailcontrol.txt
/usr/share/doc/debian/bug-reporting.txt
/usr/share/doc/debian/constitution.1.0.txt
/usr/share/doc/debian/constitution.1.1.txt
/usr/share/doc/debian/constitution.1.2.txt
/usr/share/doc/debian/constitution.1.3.txt
/usr/share/doc/debian/constitution.txt
/usr/share/doc/debian/debian-manifesto
/usr/share/doc/debian/mailing-lists.txt
/usr/share/doc/debian/social-contract.1.0.txt
/usr/share/doc/debian/social-contract.1.1.txt
/usr/share/doc/debian/social-contract.txt
/usr/share/doc/debian/source-unpack.txt