I'm here, so I'll reply to that. Since ABC is a stand alone challenge, I think it needs to be posted and tagged as such. If it does work as a Short Affair, with the prompts you're given, you might be able to post it with both tags, but it should be designated as part of your series within the ABC challenge. You might post a link to it under the Short Affair heading, rather than post it twice.
Does that make sense?