The tag implication #42704 cavern -> cave has been rejected.
Reason: While cavern is sometimes defined as being synonymous with cave, its wiki apparently defines it more specifically as "A chamber (typically large) in a cave.". By this definition, an implication is appropriate.
For example, this is a "cave" but not a "cavern", since only the entrance is seen. post #3036198
Meanwhile, this is a cavern, a chamber in a cave. post #1190156
EDIT: The tag implication cavern -> cave (forum #322296) has been rejected by @gattonero2001.
Updated by auto moderator