When you are in the Redzone and you hold your hand below the table or hide it so players can't see how many cards you have remaining. There is no actual penalty for this, but you can create a house rule.
Immaculate Deflection
A deflection card that has the ability to block a bootleg if in a set or streak.
In Passing (En Passant)
The act of stealing a set in the same turn you do not have a set or a streak but not having to pick up any cards prior.
Intentional Grounding
Discarding before picking up a card on purpose when you don't have any sets or streaks.