I like the term Guest, and always hope that once over the threshold they ARE OURS FOR LIFE, HAHAHAHAHAHAHAH!!!!!
I thought that it was (thanks to Max) an elegant way of dealing with what was at one time a very, very serious problem that threatened to kill this place completely. It also requires the regulars to be patient, and hints to the guests that they might try and act like guests. Of course some people don't respond to these kinds of signals, but what can you do.
yours, Peter T.