Since that was your first post, Welcome to the forums. However, as a new member, we have limits on what new people are allowed to do. You would not believe (or who knows, maybe you would) how many times someone becomes a member just to post an ad for diet pills, "little blue pills" that act as marital aids, or various escort services. As a moderator, I see a lot of these new posts and immediately have to erase them for direct violation of the spam policy.
Mike Krailo's suggestion to look at Jon's post in the "Similar Threads" list is excellent and likely to be authoritative since Jon is the site's owner. It lists various "tests" for detecting spam and the rationale for many of them. I'm betting that you tried to post something with a link in it, which is the most common issue for new members. But only time will tell. In a way, the fact that you got your question through this far is a sign that it is probably just one of the new-member limits that will go away eventually.