3) topic is a single tag, unconventionally fused (i.e. "Unconventional [some-tag] Fusion") - a single specific tag is chosen for a given fortnightly challenge and can be "fused" with any other uncommon tag (eg. one time it might be "Unconventional
chess Fusion", and users may release a
chess +
cryptic-clues puzzle or a
chess +
rebus puzzle, etc); single fusion tags would be suggested in the same way as other fortnightly challenge topics