Anything about rope.
If you do not know beyond a shadow of a doubt that a suspension point is definitely good enough then it's NOT good enough. If you do not have the necessary knowledge to judge if an unfamiliar suspension point is good enough yourself. Then you should set about acquiring that knowledge or just not use it. I honestly think that having the ability to judge the appropriateness of a suspension point is an essential skill for anyone who's going to suspend in different locations. And yes, I apply that to suspension points in clubs and at events too. I've refused to use points in clubs because for one reason or another I wasn't happy with them. And you cannot just take it on trust and you have to be responsible for the decision to suspend on whatever it is that you do suspend on. Because... You are making the decision to hang someone's life on that thing!