I heard this one at a club match a few weeks ago:
Coach---speaking to the center ref "Ref, tell them to back off 10 yards." He turns and looks at the sideline ref and says, "Why isn't he backing them off?"
Sideline ref---to coach "Sir, you have to ask for the 10 yards."
Coach "That;s encroachment. If I have to ask for it all the time, what are we paying you for then?"