Call of Duty: Black Ops Challenges

Kills Note
There is a bug in the game with the "[Killstreak] Kills" challenges. There are only 7 (VII) challenges, but as soon as the seventh is completed, it is changed to read "VIII".

Clean House Note
The "Clean House" Elite challenge does not specify in the description in the game how many times it needs to be done to finish each tier, however, the "x/y" completion status shows the number of times. For example, "89% Complete (89/100)" for Clean House III indicates that 89 out of a total of 100 of them have been completed.