There are three options when a team member is wearing an illegal number...
1) Participate with the illegal number–direct T on the head coach
2) Change to a legal number and change the number in the book–administrative T
3) Don't participate–no penalty
Bonus: Coach raises hell because "(S)HE'S WORN IT ALL SEASON!!!!"–direct T, then another one when the team member participates. Buh-bye, coach.