Blinking character mouse is pointing at

[DLW at MIT-AI (Daniel L. Weinreb)]

I agree about boxing the character.  If the mouse if on a PLINE that
has no line on it, nothing should be boxed.  If it is immediately to
the right of the existing text on a line, it should box the whole line,
but if it is way to the right I am not sure whether it should box the
line or box nothing.  Underlining might be confusing given region
underlining (what if both are in effect; can you see it?  And would
you confuse one for the other?), and gray looks much too prominent
in the current setup.

Probably this applies to ZMAIL too: mouse-sensitivity should be done by
boxing.  In ZMAIL now, there are times when something is mouse
sensitive but you don't get any visual feedback at all.  I think our
policy should be to always provide visual feedback of any mouse
sensitive item.  So you can box it to show it is sensitive and then
invert its video to show that it is selected or currently in effect or
whatever (that is, to indicate that it has been successfully "bugged").