The tag is present in Lintian version 2.109.21. That is the most recent version we know about.
This package contains files under
/usr/share/games, such as
desktop files, icons, pixmaps, or MIME type entries, that are global
system data. The user's desktop environment will only check in the
directories directly under
/usr/share and this information
should be put in the global directory even if it is for games.
The most common cause of this problem is using a
--datadir=/usr/share/games argument to configure or an
equivalent and using the upstream installation rules. These files need
to be moved into the corresponding directories directly under