I'm guessing you are having trouble with a blacklisted word.
Words are put on the blacklist if they are naughty words.
Some words are also put on the blacklist if they are commonplace in Spammed threads. For example we can not use the word "feetball", incorrect spelling, because otherwise the BO2 forum boards get spammed by peeps advertising live streeeming of feetball matches. "Streeeming" also not allowed.
So - what do you do to work out what word is not allowed.
Create your post. Copy your post. Send.
Not allowed --> start posting your thread one paragraph at a time. Use the edit tool to go back into your post and add the second paragraph. Repeat process until you find the paragraph that is not accepted. Then narrow the process by sentence at a time.
You will end up finding the word that is causing you trouble.
Hope that helps
If there are so many issues regarding banned words in certain posts, we should know what we're working with. It would be extremely helpful if the forum moderators could create a post outlining which words are on this no-post list. They should outline both the obvious stuff (slurs, offensive stuff) and the strange stuff that takes people by surprise (the ones that seem to fly under the radar or may not be so obvious). I'm sure it would alleviate a ton of anger among people posting stuff.