*.loc files

I would post this somewhere else...but there is no where else, so i am putting it here, don't bite my head off for it.

When using quakeforge, it asks for *.loc files, i wanted to know:
1) What they are
2) How do i use them
3) Where do i get them from
4) Is there any documentation on the use of quakeforge that explains everything and every command you need to know to get the best out of it?

Dok