Oh I definitely second that Pallas 🙂 I'm a notorious Thread Derailer and I'd forget to mark my comments 'off topic' for sure. And to mark a funny comment as "heads up for a funny comment - here is the funny comment - end of funny comment" would, well, instantly take the 'funny' out of the comment 😃
I don't really see an issue with threads derailing into fun discussions. I think the recent one where we're talking about non-classical music is a great example of the topic being mostly exhausted, but now morphing into a super fun thread where people are discussing their favourite non-classical musicians.
I think a forum resembles a pub discussion, somewhat. It starts with a certain topic and then explodes in different directions without much harm, with people chiming in and others opting out. Some get a little passionate and that's okay too. In the end, everyone is slightly intoxicated, goes home and wonders how the evening got away so fast.
Wait, did I just derail this thread????