To start, the game is targeted toward mature audiences. The ESRB rated it for ages 17+, citing Blood, drug reference, intense violence, language. However, one positive thing is that COD games have a Graphic Content filter that can be toggled on. This will filter out blood, gore, and adult language.
It's apparent that the f-word is too foul to be written plainly but anything on your bottom gets the okay. We also get minor spoilers about the game's campaign, with the ACB warning about drug use. This includes "verbal references to drugs and cartels and brief sequences in which packages of white powder are seen.