/usr/share/sane/xsane/doc/index.html is in xsane-common 0.999-3ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/sane/xsane/doc/sane-xsane-doc.html
/usr/share/sane/xsane/doc/sane-xsane-doc.html