Wilderness maps? dont have a legend... what does "P" and "W" mean?

i assumed the Ps stand for parking, but it looks as though im wrong. on the map below, right in the middle of a 20 mile trail is a P! without any road marked on or near it..
if not parking, what does the P stand for? and the W?

http://www.fs.fed.us/r6/rogue-siskiyou/r...

After digging through the web site you posted above, not just the map that the link takes you to but back into the site, here's what I've come up with. I do believe that P is for parking, the doubled lined and even some of the single lines have road numbers printed next to them. I also believe that the W stands for wilderness area.

Looks like a great place to get "lost" for a while so that one can find themselves...