The Univ of Kent where I used to work have a parking policy with a standard £15 for all sorts of offences that applies to staff, students and visitors alike, but there are unmistakable signs at the entrance to the car parks so it's hard to plead ignorance.
If you don't pay up then they are registered with the DVLA as an organisation that can request the name and address of registered keepers, and they will chase you for the fine and extra costs, even through county court if it's worth their effort.
http://www.kent.ac.uk/estates/transport/parking/penalties.html
They will also clamp persistent offenders, but it's not a very effective deterrent as they only had two clamps which at one point were on the same two student cars for quite a few months, we did wonder if it was an organised plot to prevent the other student cars being clamped.