As in “wet core” – this means that the core does not have specified types. it allows the types of the arguments to pass through, in effect meaning that one doesn’t need a put for each type of possible map (@ud to @tas, etc). “By” (which is the door in hoon.hoon map logic) is an example of a wet core. When you pass arguments to a wet gate, their types are preserved and type analysis is done at the definition site of the gate.