Surely that only applies to specific topics within the 'Arms? The 'Arms section is for free discussion of anything off-topic (ie not Humax-related), but it doesn't strike me that normal standards of polite conversation apply any less than they would if we were sitting around the dinner table. The name on the door of this particular conversation is "ELO Concert on FOUR", and there is no need to drag it off topic any more than there would be if it were not in the 'Arms. That's what I think anyway, and would do even if I hadn't originated the topic.
"A gentleman is somebody who can play the harmonica, but declines to do so"