Instant, 1U (2)
Uncommon
Cast Suffocation only if you were dealt damage this turn by a red instant or sorcery spell.
Suffocation deals 4 damage to the controller of the last red instant or sorcery spell that dealt damage to you this turn.
Draw a card at the beginning of the next turn's upkeep.
Illus. L. A. Williams

10/4/2004: It means "red instant or red sorcery" not "red instant or any sorcery".
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Commander