RE: non-breaking hyphens

[Drew Adams]

> > FWIW, I suggest adding simple search and search-and-replace 
> > commands to check for such groups of "false friends".  This
> > would be in addition to the display changes that you are discussing.
> 
> What you suggest reminds UI used when trying to save a file 
> with characters
> that can't be encoded with default coding systems, i.e. that displays:
> 
>   Click on a character (or switch to this window by `C-x o'
>   and select the characters by RET) to jump to the place it appears,
>   where `C-u C-x =' will give information about it.

Maybe.  But my suggestion was to drive everything off of a user-customizable
data structure: groups of confusables together with an identified preferred
value for each group (could be just the first or last confusable in the list, or
could be a separate entry for the group).

If, for example, the UI part was to provide a query-replace-faux-amis command
for a given group of confusables (or for all groups at once), every confusable
in a given group would be sought, and the default replacement would be the
identified preferred value for the group.

If you think that the preferred value for a group might often depend on the
context (e.g. mode), then the data structure could have a 3rd field for a
predicate or mode variable (or t or nil for always).  In case of overlapping
groups and predicates, the data-structure order would govern.  And so on.