Advanced format ruling
Cursed Seal of the Forbidden Spell
Card effect (current official text)When a Spell Card is activated: Discard 1 Spell; negate the activation, and if you do, destroy it, and if you do that, your opponent cannot activate Spell Cards with that name for the rest of this Duel.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.