Board Thread:Off-Topic Discussion/@comment-26213067-20150531221400/@comment-5051846-20150722211350

Originally, -Ps were given to producers by their fans, it wasn't generally chosen yourself. It's not a huge deal though, and the fashion has mostly died out. It's also not an automatic sign of quality, there are popular producers without -P names, and dishonored producers with -P names (HorizonsP, PlantyP).