on a gnome-terminal, if you 'less' a small file, you get a screenful of rubbish from the last program to use the alternate screen image (the last invocation of less, for instance). if you do the same thing on an xterm, the alternate screen is not used and you can see that the file is short because the prompt doesn't roll off the screen...you have context. the behavior of less is severely broken on gnome-terminal. gnome terminal should either behave like xterm (it says it's an xterm) or it should have a different term{cap,info} entry...
I don't get a screenful of rubbish in the latest stuff, though the behavior is somewhat different (gnome-terminal clears the screen before entering less, xterm does not). Either behavior is sane though so I think a separate terminfo entry would just be inconvenient. Will reopen the bug if I can reproduce the rubbish.