> The keypad and cursor keys have two modes - 'normal' and 'application'.  If
> you hold down <control> and press the middle mouse button when in your
> xterm window, you can see that application mode is normally off.  To enable
> it, programs can use the keypad() curses function.  This uses the termcap
> entries 'ks' and 'ke' to turn application mode on and off, respectively. 

Thank you for the hint, I feel more comfortable now.  In NetBSD, xterm
emits "application mode" escape sequences when it ought to.

On HPUX 10.20, xterm emits "normal mode" escape sequences regardless of
whether "application mode" keypad and cursor keys are set.  HPUX's
/etc/termcap reflects this.  Slackware 8.0's /etc/termcap is the same.
Sure enough, when I log into my NetBSD system from an HPUX 10.20 xterm,
the cursor keys do not work in vi.

http://cvsweb.xfree86.org/cvsweb/xc/programs/xterm/termcap?rev=3.28&content-type=text/x-cvsweb-markup
That's official enough for me.

Thanks!

Ben