1. All challenges and stories must address, illuminate, or be relevant to Harry Potter and the Half-Blood Prince. This means that a story may be told in flashbacks as long as it relates to sixth year. This also means that studies of a character's past are admissible as long as they shed light on their behavior or portrayal in the book.
2. Only pairings that are expressly canonical are allowed. So no Sirius/Lupin or Harry/Draco pairings despite obvious subtext and innuendo.
3. Any and all ratings are allowed as long as they don't contradict canon. So no hot and heavy Ron/Hermione humping in stairwells because that clearly didn't happen in the book.
4. Stories must be at least 500 words. Please put all stories behind an lj-cut.