Tip Income
  
No, this isn't from whispering to bettors on horses at the track that Not Yet The Glue Factory is going to win by a furlong in the third. But if you were a tipster, that'd be cool. And no, it's not for ratting out your mob friends to the cops. They pay you dough...you pay taxes on those tips, maybe?
No. Tip income is just the income that actors make from serving you drinks, food, and dessert with a smile. It's kind of a separate category, because tip income is supposed to be declared and taxed. But, in fact, a huge portion of tip income is paid in cash. Servers pocket the money and don't pay. All part of the little Underground Economy.
Anyone seen the Hulu series The Handmaid's Tale?