I just read we should never just call to 4bets, only fold or raise. Is this right? It's confusing because Pokersnowie advises calling sometimes as weak as AQo.

The general guideline for 4bet sizing is IP 2.2x3Bet, and OOP 2.5x3Bet. Very rarely regs don't know "correct" sizing and make 3x my 3Bet they being IP. I have AK, and by my experience, they always have a strong hand, and I can't just fold AK PF. I have taken a guideline to shove with AKs, and usually fold AKo PF, except if they are wide 4bettor (usually not enough HUD stats to know that).

So, what are your guidelines facing 4Bets at the lowest stakes? Especially I would happy to know what to do with some "semi-premium" hands, QQ and AK (sometimes JJ) when the villain makes 4Bet size of 3x my 3Bet. I will post some hand histories later.