AR pistols- and all the irregularities

It seems I heard somewhere that pistols can’t have a folding buffer tube. Is that true?

Maybe it’s like all the other “maybe-maybe not” and “that doesn’t make sense” stuff?

With the way ATF is going who knows what is and isn't legal. A lot of discussion on things like this was lost when armory went down. Magpul AFG used to be legal, now I'm told it's not. The last thing I saw was implying that flip up iron sights or anything that indicates it could be used two handed like a carbine or SBR makes it a SBR. Who knows anymore.

Classic "confusion to the enemy!" And in case y'all ain't figgered it out yet, we're the enemy.

Terry