Actually IndySam... you are incorrect that this has not been ruled on, the following Q&A posts all deal with this topic:
http://forums.usfirst.org/showthread.php?t=11308
http://forums.usfirst.org/showthread.php?t=11347
http://forums.usfirst.org/showthread.php?t=11162
These state pretty clearly that you will be asked to change your shirt ESPECIALLY if you have designed it that way on purpose. Definitely not GP.
ScottieDo555: it is not only important to real the manual but it is also the responsibility of every team to monitor the Q&A forum.