Using openbox, i sometimes mark a window "always on top" with the
window context menu.  According to xprop, this apparently adds the
_NET_WM_STATE_ABOVE flag to the _NET_WM_STATE(ATOM) list.

I believe the same thing is done by lxterm (LXDE's terminal emulator)
when it is run in full-screen mode.

However, if i run ssh-askpass from such a window (or from any other
window, when such a window covers the region of the screen ssh-askpass
pops up), then the ssh-askpass window is obscured, and the keyboard is
not properly grabbed (i can M-Tab to the dialog window, and off of it
again).

This seems buggy to me, though i confess i don't fully understand
_NET_WM_STATE.  Perhaps ssh-askpass should also set
_NET_WM_STATE_ABOVE before showing the dialog box?

Regards,