As an example I had an opponent who was milling himself to stick flashback-able sorceries and powerful creatures to resurrect, am I allowed to look thru and know whats in their graveyard? Last time I requested he said no so im left to assume its a consent thing, like they may choose to not allow me info of their graveyard to keep their strategy secret. I know from an opponent mill deck i have to reveal the NUMBER of cards in my graveyard at times.
The graveyard is a public zone, and you’re allowed to know which cards are in a public zone. While your opponent doesn’t have to tell you which cards are there, but they then have to allow you to get that information yourself, i.e. by looking through their graveyard. They cannot deny you access to that information.
