"On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."
People here love to quote that, but they rarely mention the very next sentence:
“Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic.”
Left to their own devices, people tend to devolve to the lowest common denominator-type news. I wish the moderators here (since we have them) would do a better job of keeping such “Off-Topic” stuff off the front page.
There's some subtlety to the arrangement of the words. "off-topic, but interesting" has the implication that 'interesting' is preferred. "interesting, but off-topic" implies that as interesting as something might be, it is still off-topic and therefore might not be permitted.
I did think about it. Before I posted I spent more than just a small bit of effort. I still don't see what the difference actually is though. Yes I know what "but" means. I know all those words... but...
I do not see any actual difference. Anything you apply those two descriptions to are both "off-topic" as well as "interesting", according to those descriptions. The "but" does not make any difference at all as far as I can see. The other replies say there is a preference implied (I already knew that that was the intention), but as I just wrote, however you parse it, you end up with both attributes and I don't see any preference actually being applied. I see the attempt, yes, but I don't see that there is any effect.