Select "Help + Options" at the main menu. Select "Unlock Code", the enter one of the following case-sensitive codes to activate the corresponding weapon tag to use through the "Armory Weapon Customization" option. A bell followed by a woman screaming will confirm correct code entry.

Effect	Code
AMD VISION square tag (blue)	4MDB4quprex
AMD VISION square tag (red)	AMD3afrUnap
ATi square tag	AT1hAqup7Su
Alienware black dog tags	Alienwarec8pestU
Alienware symbol	Al13nwa4re5acasE
Australian flag	AUS9eT5edru
Austrian flag	AUTF6crAS5u
Belgium flag	BELS7utHAsP
Blacklight and crossed swords	R41nB0wu7p3
Blacklight logo chip	Ch1pBLuS9PR
Canadian flag	CANfeprUtr5
Danish flag	DENdathe8HU
Dutch flag	HOLb8e6UWuh
E3 dog tags	E3F6crAS5u
Famitsu Magazine dog tag	Fam1tsuprusWe2e
Finnish flag	FINw3uthEfe
French flag	FRApRUyUT4a
German flag	GERtRE4a4eS
Hong Kong flag	HOKYeQuKuw3
Indian flag	INDs4u8RApr
Irish flag	IRE8ruGejec
Italian flag	ITAQ7Swu9re
Jace Hall Show logo	J4ceH4llstuFaCh4
Japanese flag	JPNj7fazebR
Korean flag	KORpaphA9uK
Mexican flag	MEX5Usw2YAd
New Zealand flag	NZLxut32eSA
Norwegian flag	NOR3Waga8wa
Orange Scorpion logo chip	Ch1pMMRSc0rp
Order logo chip	Ch1p0RD3Ru02
Pink brass knuckles	H4rtBr34kerio4u
Portuguese flag	PORQ54aFrEY
Razer logo	R4z3erzu8habuC
Russian flag	RUS7rusteXe
Singaporean flag	SINvuS8E2aC
Spanish flag	ESPChE4At5p
Storm Lion Comics logo (shaped)	StormLion9rAVaZ2
Strom Lion Comics logo (rectangle)	St0rmLi0nB4qupre
Swedish flag	SWEt2aPHutr
Swiss flag	SWIsTE8tafU
Taiwanese flag	TAW8udukUP2
UTV Lightning logo chip	Ch1p1GN1u0S
United Kingdom flag	UKv4D3phed
United States flag	USAM3spudre
Upper Playground logo	UPGr0undWupraf4u
Yellow teddy bear	Denek1Ju3aceH7
Zombie Studios logo chip	Ch1pZ0MB1Et7