When we lift in the gym, we basically make our own rules regarding a PR. The foot placement, the speed, or the lifting accessories used, all depends on you.
You are free to use lifting straps, knee wraps, wrist wraps, knee sleeves, any kind of lifting shoes or belt. However, in powerlifting competitions, things change a little.
Just to clarify things, a PR in a competition means exactly what it means in the gym, but with stricter rules.
The rules include squatting below parallel, using a “thumbs around” grip for the bench press, and locking the knees for the deadlift.
There are many more lifting requirements as well as rules on lifting accessories and other things. In addition, for each attempt, athletes have to wait for the signals of the Chief Referee, which makes things more complicated.
Therefore, a PR obtained in the gym is very difficult, if not impossible, to reproduce in a powerlifting competition.