I've seen it used in a couple papers, none of which are freely available, but a preview gives a couple sentences involving a P100 score here: https://scholar.google.com/scholar?q=p100+score&btnG=&hl=en&as_sdt=0%2C33&as_vis=1 and in the abstract here: https://arxiv.org/abs/1604.08088
What is the meaning / derivation of a P100 score, in machine learning image recognition?