xterm et al - window is cleared after less etc

[Jan <jandersen striva com>]

Sorry to post this question to this list, but I'm not quite sure where
to go; and anyway, it is probably something everybody here knows the
answer to.

I am getting increasingly annoyed by this misfeature: when I leave a
full screen application such as man, less or vi the screen is cleared,
so I can't see what I was just looking at. I know there is a way to turn
it off - but which? It goes away BTW when I set TERM to something else
than xterm, but that is at best a bad workaround.

/jan