E46 F10 W204 W212
The cog adjuster takes up the play between the shoe and the drum (inside of rotor hat). The cable adjuster takes up the cable slack. Both are adjusted as a system.Yeah, but OP is asking WHY to do it this way instead of at the handle. I have always wanted to know as well. I don't see why it matters which end of a cable gets tightened, but if there is a real reason out there I'd like to hear it too.
Loosen cable, adjust cog, tighten cable. Per TIS, parking brake must hold the car in 4-7 clicks. I always adjust mine to 4 so it lasts a while.