I didn't look at the file but it sounds like position.
If it's so then you could create a new small panel, move it around, make it larger/thinner and see if the values change.

Excellent idea to create an additional panel, just for testing.
Here are the results for p:
p=12 : bottom border
p=11 : upper border
p=5 : left border
p=1: right border
p=8: bottom left corner
p=6: upper left corner
p=4: bottom right corner
p=2: upper right corner
p=0: free position

x and y indicate the position,
however:
when the panel is located on a board, a single value is active.
when the panel is located in a corner, none of the values is active

What mean the values p=, x= and y=