Config is the heart of your addon, no matter how nice model and textures you have, they are empty shell without a configuration to make it all run in-game.

Configs in general

Marker lights

CfgMods to identify your mod to ArmA 2.

Dispersion for weapons.

Pilot proxy rtm file creation.

Custom face, how to add custom face to your soldier.

Shotgun config for real shotguns.