Can someone educate me as to what makes a motherboard "supported" or not?

I don't know squat about mining generally, but in building basic linux servers over the years I've never really been concerned with motherboard support.

I ask because I was considering playing around with nvOC on an old HP linux server with a single 1050ti I had laying around.  Wanted to get familiar with nvOC working with nvidia cards before I buy and build out a real rig.

However, I saw something about supported motherboards and figured I would ask before I wasted my time.

Thanks!