Cheats for Halo: Reach

Assault Rifle	Have played the Halo Reach Beta in May 2010
Bungie Nameplate	Activate blue flames through iPhone/iPod app to unlock
Designated Marksman Rifle (DMR)	Subscribe to the Bungie Pro hosting service
HALO	Unlock the Halo, Halo 2 and Halo 3 nameplates
Halo 2 logo	Have played Halo 2 on Xbox Live before April 15, 2010
Halo 3 logo	Play any Campaign level in Halo 3 while connected to Xbox Live
Marathon Durandal symbol	Have Marathon Durandal in your recently played games list and login at Bungie.net
MJOLNIR Mk VI helmet logo	Unlock any 4 of the Halo PC, Halo 2, Halo 3, Halo 3: ODST or Halo Reach Beta nameplates
ODST logo	Play Halo 3:ODST while connected to Xbox Live
Original Halo logo	Register your Halo PC product code at Bungie.net
Star Nameplate	Activate through Bungie Mobile iPhone/iPod app
The Septagon (7th Column symbol)	Join Bungie.net and login with your Gamertag's email address

Carter's Helmet	Clear a Campaign mission on Legendary without dying.
Emile's Helmet	Earned a Bulltrue medal in either multiplayer or Firefight Matchmaking.
Jorge's Helmet	Earn a Killtacular in multiplayer Matchmaking.
Jun's Helmet	Kill 100 enemies in a row without dying in either the Campaign or Firefight.
Kat's Helmet	Avenged a teammate's death in multiplayer Matchmaking