In reply to Robert Durran:
> Bouldering is presumably different.
No it's not... other than since boulders are so short, you can't claim onsight on them and have to go with flash.
As stated, onsight for roped climbing is to climb cleanly the route without any prior knowledge. If you fall or slip, you haven't climbed it cleanly. However, if you downclimb to the ground... it's still ok. Jumping off on purpose is a bit of a gray area, but accordin' to my ethics it's failing and I ain't writin' it as an onsight.
That said, as with all these non-professional treads... I don't really care a rats ass... nor should anyone else. The only thing that matters, is that the person is honest to them selves.
Eg. have a look at this route and the public logbooks:
https://27crags.com/crags/nalkkilan-slabi/routes/smooth-operator-126644
Eg. Pasi Jokinen slipped off as soon as he stood on the wall (and no, that ain't the crux). Hence he claimed redpoint as he got it on the 2nd go, even though on principle he basically onsighted the whole route (except for the 1st foot placement).