Submitted by: John Watson Sensei
Recently the Teaching & Technical Committee (TTC) was asked to clarify whether T-shirts, singlets or other similar garments, could be worn underneath gi tops. For normal training in the dojo, the tradition is that men don’t wear anything under the gi top and that women do wear a T-shirt. 

However, for cultural, religious or medical reasons it is permissible for males to wear a T-shirt under their gi. Therefore, in those cases, it is polite for males who are required to wear a T-shirt to explain to their instructor the reason for doing so. This notification is particularly important when they visit another class or attend a special training with someone other than their usual instructor. 

In that situation, a person should advise the new instructor before the class, that they are aware of the traditional dress code, and then give their reason for not being able to follow it. For both women and men, the T-shirt should ideally be white and plain, and not stand out underneath their gi.