/usr/share/man/man3/XIUngrabKeycode.3.gz is in libxi-dev 2:1.7.1.901-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man3/XIGrabButton.3.gz
/usr/share/man/man3/XIGrabButton.3.gz