WARNING: The files in the system/ tree should not be modified.

Future upgrades will overwrite these files without regard for local
modifications. This is necessary to allow alteration of system internals
to support new features, correct bugs, change implementation classes, etc.

If you make changes to these files, you should back them up across upgrades,
and are solely responsible for re-applying local changes.

Please consider filing enhancement requests if there are changes you feel
are necessary so that future versions might better accommodate your needs.