Hi! I'm a Camping Merit Badge Counselor, Scoutmonster, and a member of OA. (the Camping Honor Society.)
Camping is in a tent, or on the ground out side,(or, I suppose, a platform) not in a tent, in the jargon, "under the sky." I'll count sleeping in a cave. For unit activity, perhaps a cabin, but that won't fulfill any but the barest of requirements.
Actual practice, and you can flame me all you want:
Scout "A":
"To fulfill my last three nights of camping for this (Camping)Merit Badge, I want to go with my sister and her husband to Rushing-water-deep-in-the-woods State Pa