CoD's community manager Robert Bowling has been testing four new multiplayer modes over the weekend, with the potential for adding them as new playlists.
A developer posted a message on his blog asking for volunteers to help test out four new game types last Friday.
Bare-bones Team Deathmatch immediately took our interest, as it removes perks and kill streak rewards, leaving you with just your skills weapons to fall back on.
Other modes included Hardcore HQ, which supposedly encourages more tactical gameplay and communication by increasing damage, removing the HUD and enabling friendly fire. Hardcore FFA similarly applied tougher conditions to the free-for-all mode.
Multi-bomb search and destroy was also tested, which blessed every member of the attacking team with a bomb.
Bowling has stated that he'd like to make the testing a weekly event, so if you fancy getting in on an unofficial beta test for extra CoD 4 content, take a wander over to his blog.
There's no word yet whether these modes were popular enough to be included as additional content, but we'll let you know as soon as we find out anything.