Overwriting in ArmA config.

You can overwrite or override specific sections of other configs (Default ArmA, or addon configs etc). Important is that you specify the addon which you overwrite/override, aswell as the addons it needs loaded, in the requiredAddons list within cfgPatches.

This example shows how to use override M4/M16 sounds by RobertHammer's

// Replaces M4/M16 Sounds by RobertHammer's M4/M16 Sounds
class CfgPatches
{
	class SIX_rh_m4_soundpack
	{
		units[] = {};
		weapons[] = {};
		requiredVersion = 1.15;
		// CAWeapons/CAWeapons3 because those are the ones we override.
		// RH_M4 because thats the addon the sounds are used from
		requiredAddons[] = { "CAWeapons", "CAWeapons3", "RH_M4" };
	};
};
 
// Inheriting the different firemode classes, so we can use them later on
class Mode_SemiAuto;
class Mode_Burst;
class Mode_FullAuto;
 
class CfgWeapons
{
	class Rifle; // We do not need to define the class rifle here, only inherit
	class M4: Rifle // We redefine the M4 class here because want to override certain properties
	{
		reloadMagazineSound[] = {"\RH_m4\sound\M4_Reload.wss", 0.001, 1};
		class Single: Mode_SemiAuto
		{
			sound[] = {"\RH_m4\sound\m4s.wss", 5.62341, 1};		
		};
 
		class Burst: Mode_Burst
		{
			sound[] = {"\RH_m4\sound\m4s.wss", 5.62341, 1};
		};
 
		class FullAuto: Mode_FullAuto
		{
			sound[] = {"\RH_m4\sound\m4s.wss", 5.62341, 1};
		};
	};
 
	class M4A1SD: M4AIM
	{
		class Single: Mode_SemiAuto
		{
			sound[] = {"\RH_m4\sound\m4sd.wss", 0.01, 1};
		};
 
		class FullAuto: Mode_FullAuto
		{
			sound[] = {"\RH_m4\sound\m4sd.wss", 0.014125, 1};
		};
	};
 
	class M16A2: Rifle
	{
		class Single: Mode_SemiAuto
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};
 
		class Burst: Mode_Burst
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};
	};
 
	class m16a4: M16A2
	{
		class Single: Mode_SemiAuto
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};
 
		class Burst: Mode_Burst
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};	
	};
 
	class m16a4_acg: M16A2
	{
		class Single: Mode_SemiAuto
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};
 
		class Burst: Mode_Burst
		{
			sound[] = {"\RH_m4\sound\m16s.wss", 5.62341, 1};
		};	
	};
};

Weapon model and picture override.

This example shows how models and some pictures are replaced by some of the best custom weapons out there.

// Replaces Many Models by some of the best custom weapons out there
class CfgPatches
{
	class SIX_Repl_WeaponModels
	{
		units[] = {};
		weapons[] = {};
		requiredVersion = 1.15;
		// CAWeapons/Weapons3 because we override them,
		// RH_M4, Vilas_mod_models, RHS_Weap and Ska_Racs_Wp
		// because we use the models/pics from them
		requiredAddons[] =
		{
			"CAData", "CAWeapons", "CAWeapons3",
			"RH_M4", "vilas_mod_models", "RHS_Weap",
			"Ska_Racs_Wp"
		};
	};
};
 
class cfgWeapons
{	
	// Base Classes
	class Rifle;
 
	// BI Class overwrites
	class AK74: Rifle
	{
		model = "\RHS_Weap\RHS_AK74";
		picture = "\RHS_Weap\Ed\AK74pic.paa";
	};
 
	class aks74pso: AK74
	{
		model = "\RHS_Weap\RHS_AKS74PSO1";
		picture = "\RHS_Weap\Ed\AKS74PSO1pic.paa";
	};
 
	class AKS74U: AK74
	{
		model = "\vilas_mod_models\AKs74u";
	};
 
	class AKS74UN: AKS74U
	{
		model = "\RHS_Weap\RHS_AKS74PBS3";
		picture = "\RHS_Weap\Ed\AKS74PBS3pic.paa";
	};
 
	class AK74GL: AK74
	{
		model = "\RHS_Weap\RHS_AK74GP30";
		picture = "\RHS_Weap\Ed\AK74GP30pic.paa";
	};
 
	class G36a: Rifle
	{
		model = "\vilas_mod_models\G36";
	};
 
	class G36C: G36a
	{
		model = "\vilas_mod_models\G36C";
	};
 
	class G36K: G36a
	{
		model = "\vilas_mod_models\G36_K";
	};
 
	class M4: Rifle
	{
		model = "\RH_m4\RH_m4.p3d";
		picture = "\RH_m4\inv\m4a1.paa";
	};
 
	class M4AIM: M4
	{
		model = "\RH_m4\RH_m4aim.p3d";
		picture = "\RH_m4\inv\m4a1aim.paa";
	};
 
	class M4GL: M4
	{
		model = "\RH_m4\RH_m4glacog.p3d";
		picture = "\RH_m4\inv\m4a1gl.paa";
	};
 
	class M4A1SD: M4AIM
	{
		model = "\RH_m4\RH_m4sd.p3d";
		picture = "\RH_m4\inv\m4a1sd.paa";
	};
 
	class M16A2: Rifle
	{
		model = "\RH_m4\RH_m16a2.p3d";
		picture = "\RH_m4\inv\m16a2.paa";
	};
 
	class M16A2GL: M16A2
	{
		model = "\RH_m4\RH_m16a2gl.p3d";
		picture = "\RH_m4\inv\m16a2gl.paa";
	};
 
	class m16a4 : M16A2
	{
		model = "\RH_m4\RH_m16a4.p3d";
		picture = "\RH_m4\inv\m16a4.paa";
	};
 
	class M16A4_GL : M16A4
	{
		model = "\RH_m4\RH_m16a4gl.p3d";
		picture = "\RH_m4\inv\m16a4gl.paa";
	};
 
	class m16a4_acg: M16A2
	{
		model = "\RH_m4\RH_m16a4acog.p3d";
		picture = "\RH_m4\inv\m16a4acog.paa";
	};
 
	class M16A4_ACG_GL : M16A4_GL
	{
		model = "\RH_m4\RH_m16a4glacog.p3d";
		picture = "\RH_m4\inv\m16a4glacog.paa";
	};
 
	class PK: Rifle
	{
		model = "\vilas_mod_models\PK_MG_proxy";
	};
 
	class M249: Rifle
	{
		model = "\Ska_Racs_Wp\Ska_M249";
		picture = "\Ska_Racs_Wp\Editor\M249pic.paa";
	};
};