You count up your cash tips at the end of the evening, and if it's a place with liquor you have to "tip" the bartender even if none of your customers ordered alcohol.
Then if you're nice liberal Mario Bitalli (sp?) you sometimes take half the tips--
Also, restaurants are responsible for making sure that the tips are reported as income for taxes.
What gets me is when you eat in a fancy place, like Ruth Chris's (twice in my whole life! Divine!!) that tip can really hurt!!
They don’t know what’s in the waiter’s pocket....and they don’t know why I gave them that money..... it would be hard to prove IMO ;o)