Rating Picture Quality For Amateur Television Operations

The P level reporting system was origionally developed in England and
eventually adopted by the rest of the world. Is's called P Level (for
picture) and ranges from P0 (no picture) to P5 (closed circuit).

P1 is visiable sync bars,
P2 is lots of snow,
P3 is some snow,
P4 is nearly snow free
P5 is broadcast quality, closed circuit.

You can also indicate color or sound as in , "Your signal is P4
with color and sound." Or "I'm getting a P3 with occasional color
and no sound" etc. Snow is the word we use to indicate noise in
the picture.  The system is more subjective than scientific
although P5 is about 200 microvolts whereas 1 microvolt is full
quieting in FM mode".