What is something you wish other dog owners would enforce more?

I absolutely detest being jumped on. Every time I go to the dog park it never fails that I will be jumped on at some point. Usually the other owner apologizes, which is nice. The thing is, they make an excuse that the dog is just too excited.

I wish more owners would work with their dogs to train them not to jump to receive attention. I try to help them out by ignoring the dog until it is calm, but not everyone does this, so the dog gets mixed signals.