I'm guessing P stands for Pekin? I don't think vent sexing is an option anymore but I will leave that one for a more experienced person to tell you. I have 5 one month olds and we are just at a limbo with what they are. They still peep so voice sexing isn't a viable option and I have no idea how to vent sex which are about the only 2 ways that you can identify sex before maturity and the drake feather comes in. Sorry I couldn't be much help