(23 Nov 2017, 4:35 pm)MurdnunoC wrote At what point does a working cease to become 'rare or odd'?

This is a good point. 

I've always reported workings that have seen branded buses working other routes, or non-branded vehicles working a route in place of a branded vehicle. I don't see this as massively beneficial, or interesting, but initially started doing it as I was aware that people liked getting pictures of that sort of working, especially when Sapphire and MAX were in their relative infancy. 

I guess instances such as, for example, an MPD appearing on the X15 are what this thread is intended for.

I think the thread has slightly lost its way, in the sense that any working that isn't 100% "correct" is now R&O. For instance, I wouldn't class a generic MAX vehicle allocated to any MAX route as rare, odd, or anything else.