no loot modfier for caster tomes?

[Aceplante]

I want to remove casting tomes from loot tables, as they allow players to get around the intentional disabling of certain spells.

I could not find a loot table or modifier where they are added, so how would I go about disabling them?

forge 1.18.2

[baileyholl]

this is controlled by the dungeon loot modifier, set the rare modifier to 0.