Blam!
From Halopedia, the Halo wiki
Blam! was the code-name for Halo: Combat Evolved before it was completed. It was used to replace the original name "Monkey Nuts" because project lead Jason Jones could not bring himself to tell his mother he was working on a game called "Monkey Nuts."[1]
"Blam!" is now used to censor curse words on the Bungie.net forum, the Weekly Updates[2], and to censor inappropriate content names in Halo 3. It is most likely a tribute to the word itself. Many non-Bungie users have caught the habit and use it abundantly.
The word was thought of because Bungie's Chicago office was located near a very busy street that had numerous near-collisions between cars. Robert McLees would yell "Blam!" so there was a sense of completion.
An occasional glitch occurs on Halo 3. A player can name a map or a game variant anything, and no matter the result, a notice of censorship will pop up telling you that its name must be "Blam!".
For some reason, using "assault" in your map names or descriptions causes it to be censored, even though the default description of an edited Assault variant has the word (and so is censored). "Long" is also censored, and so is "big" (even though matchmaking has "Big Team Slayer").
