/usr/share/man/man3/joystick_z.3.gz is in libsvga1-dev 1:1.4.3-31.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man3/joystick_getaxis.3.gz
/usr/share/man/man3/joystick_getaxis.3.gz