I would imagine there is no padding. At most events now you are only allowed 2 layers. Padded shirts class as 2 layers, so wearing a shirt underneath (unless it is cut around where the padding is) is not allowed. This also causes problems for elbow pads.
Ok you might not get caught out a lot but it is a pain in the ass if you have to start taking your pack and shirt off before the game can start.
I Think Planet have thought of that!!!
Nige