RE: Regarding smerge upper/lower; needs NEWS

[Drew Adams]

> > but if the windows/buffers are labeled, as is done in Ediff ("A", "B")
> > then there is no ambiguity, regardless of how or where they might
> > be displayed.
> 
> Check the subject: it says "smerge".  That's a minor mode which operates
> 100% within a buffer (any buffer), so there's no labeling of buffer or
> window involved.

If you don't have some visible object to label then
use the label of the existing visible thing you have.

E.g., if the only visible distinction is the use of
different faces then use the face names.

Users can at least use `C-u C-x =' to see what those are,
if the names are not clear.  (But if the names are not
clear then maybe a renaming is in order.)