Player Uniform Number Verification Policy
In looking through the pre-match responsibilities for the referee, nowhere does it say to verify the uniform numbers. It simply says to "verify with each coach that all players are wearing legal uniforms and equipment." There is nothing to back up requiring players to show their numbers. Verifying the numbers is a courtesy that officials have done in an attempt to prevent a delay at the start of a match due to wrong numbers.
Many coaches now allow their players to wear sweatshirts or t-shirts when warming up. Some coaches want their players to wear them the entire time and do not want officials disrupting their warm-up routine being disrupted with officials asking players to show them their numbers. To avoid unnecessary confrontation, it might be more effective if the officials offered to verify the uniform numbers prior to the start of the match or prior to their warm-up.
The official policy of the TPCVOB, in accordance with the WIAA opinion, is as follows:
We will continue to encourage officials to provide the "courtesy" of verifying numbers for preventative reasons. However, if numbers can't be seen, then we will just "assume" the roster is correct. If there is an illegal substitution due to wrong number, then oh well. Our comment to the coach will then have to be "sorry, we were not able to provide the "courtesy" of verifying your players’ numbers prior to the match due to warm-ups/t-shirts/etc. In addition, officials SHOULD make sure during the captains meeting to ask coaches if their players have "legal" uniforms (preventative effort).