I'm trying to post a campaign starting in 23 hours. Why is it being marked as spam?
Thank you in advance for rectifying this, but could you also you explain what's triggering the spam filter, so I can avoid this with future posts.

I've just solved it- The post contained a "mildly naughty word".

Could I instead turn this post into a suggestion?
I have absolutely no issue complying to censorship on someone else's platform, but merely marking the post as spam is extremely ambiguous and doesn't communicate your intent. Meaning, that I have no idea what action I need to take to adhere to your wishes, or if there is even an issue my end.

For the sake of anyone following me, would it be possible to instead flag the post of profanity, or something? Maybe even giving the OP the chance to edit the post?

Actually, edit:
It was the "(AEST)" in the title... Putting a time-zone in the title...
I discovered this, when I realised it was missing from my 'censored post', updated it, and it too, has now been marked as spam and I have been locked out from editing that post also.

It's an automated algorithm that checks how closely a post matches known 'spam' items.  It's not triggered from a specific keyword or entry, but a match overall.

The answer here is not to combat the spam filter by posting 4 times, but by contacting a moderator so that we can mark the post as 'Not Spam' and help the system learn/tune.  In any event, it looks like you're well on your way here.

Yeah, I managed to get a copy of the post up without getting flagged. The only difference between accepted and filtered in this instance was the "(AEST)" in the title.

If the spam filter uses machine learning, then I guess no one would have any idea why that was flagged.