The P stands for Pan european..
Its the country designator..
In the past, Toshiba made TV's specifically per country, so the UK had a DB (B for British?), DD for Germany, etc. The differences where mainly due to it being cheaper to make the model specific, as in the UK, we have a slightly unique PAL setup, and the french have PAL and SECAM, etc, etc..
Well, nowadays, they make sets that support all main formats PAL/SECAM/NTSC... and so the same set can be used anywhere in europe (well just about), as long as its 240V...