Sorry

Enchantment, UU (2)
Before playing any spell, if a copy of that spell card is in any graveyard, the spell's caster may say "Sorry." If he or she does not, any other player may counter the spell by saying "Sorry" as it is cast.
If any player says "Sorry" at any other time, Sorry deals 2 damage to that player.
Illus. Kaja Foglio

Crystal Keep Rulings Summaries

• All tournament formats have banned cards from Unglued.
• Note - Also see Unglued rulings, Rule 507.

Format Legality	Banned in Vintage, Legacy, Extended, Standard
Printings (1/1)	Unglued (Uncommon)