P plater-part of the gradual liscensing system.

So, before you get your full licence, you're put on a 'provisional' one for a certain time. Provided you don't do anything really stupid and follow all the restriction, you'll be on a full licence in about 2yrs. (I was on P plates for 2yrs)

http://www.dpi.wa.gov.au/licensing/l...ivers/1473.asp

I hope that makes some sense...