Basically you can get penalties for swearing, throwing gear, talking after shot, roster or staff leaving your pits, talking from pits, over shooting(bounce balling) someone who is clearly out, gun shooting over 300fps, gun shoot faster than 12.5bps, yellow gear, playing when your hit, etc. Those all vary.
The main ones are the hit penalties. If you play on and have an obvious hit on your body that you can feel and see it that is a major penalty. If the ref thinks it is an non obvious hit ( hopper, pods, pack ) then it is a minor. However most refs are understanding and won't throw a minor unless they think you know you got hit, shot someone out after being hit, or did a major move after getting hit. If you get hit in the hopper or pack/pods and you flinch and/or tuck into the bunker or move out of the way a little after you get hit in the hopper or pack the ref is going assume you felt a ball hit you, you didn't call for a check, and you will get a minor or major for it. Depends on the ref honestly and if they think you clearly played on. If you get hit in the arm or something you should be able to look and see if you got hit, and you call for a check for it, that is a minor I believe. If you get bunkered and he shoots you then as he passes you, you spin and shoot him real quick while he is bunkering you that is a major.
got to say though , over here in the UK Sites don`t use the Pits to come charging out to play after getting the penalties and having so many seconds before they can come out then It`s a 50/50 chance to see them make it. and to be honest , that was the Best part because the other team know this then makes the team WAKE UP. over here In the UK It`s quite tame really. It`s a shame.