'Class B' Uniform - What is it?

These uniforms are really known by the Boy Scouts of America as 'Activity Uniforms'.

The most 'common' Class B Uniform is our Troop T-shirt. (Our current Troop T-shirt is the dark green shirt with the white & gray design on the front.) But the Class B's also include all Summer Camp T-shirts, Shirts purchased from the Scout Shop, or others that have BSA designs or logos on them. Worn with pants or shorts that are appropriate for a Scout Outing. (It is recommended that each Scout purchase 2 Troop T-shirts.)

Also see "What is an Activity Uniform?"