The Verification is a consumable item that can be used on maps placed in an item frame to prevent them from being placed in the cartography table. This means that ‘verified maps’ cannot be scaled, locked/unlocked or copied. Trying to use the seal on maps via other methods will not work.
The Verification Seal belongs to the Fubuki collection and does not have a prerequisite to unlock it's recipe. The Verification Seal has a cheap cost to craft requiring:
The Verification Seal can still be used as a component in crafting (e.g dying wool, candles, terracotta, etc.).
Verified maps can still be placed in the player's crafting menu and crafting table but trying to copy a verified map will refuse to craft and instead return the items back to the player.
Using the Verification Seal on an already verified map will consume the seal effectively wasting the item.