A Shaffer is when play has stopped due to a point scored, etc. and you sneak across the table to drop the ball into your opponent's cup. A Shaffer can be prevented by leaving your paddle on top of your cup, unless your opponent is a dirty, dirty whore.

Legend has it that the Shaffer is named after Shaffer, though that sounds pretty unlikely.

Assveal, it's pronounced 'Shay-fer' and probably not spelled Shaffer, as that would be pronounced 'Shaff-er'. It is likely spelled similar to Schaffer or Schafer.