Ah, come on now Peter...
If you wan't to see how they "work" and what they are simply open the .inc file for the specific target you're compiling for, it's located in the root of the PBP folder. For the 16F886 the fileneme is 16F866.INC and looks like this:
Why did you go open the M16F88x.inc ? (I don't even have that file on my system.)

It's not THAT hard...but you have to actually read ;-)