Porting question

What's the difference between j port and p port? I have a friend that was talking about how he ported his 12A, and i'm not really sure as to the details of what he did. I was hoping that would refresh my memory, and i also don't know the difference. thanks guys.

this site talks about different 12 A ports
http://home.iprimus.com.au/bluey3/portsPage/ports.htm

i think a p port is just another word for peripheral port

The p-port and J-port are the ports that require large amounts of metal to be cut out of the rotor housing to get more air to the motor..They provide lots of top end power, but low end power is not there..Both ports are for drag cars..They have no business on a daily driver and require huge amounts of maintainence and $$$$$$ to keep running...I would stick with a street port on that 12a....
Been there, done that..

Thanks, that website totaly helped out. ends up this guy has a 1st gen rx with a j port which he takes to autocrosses. thanks again