This ticket might be a documentation ticket. If we
don't change the software, the current behaviour must
be documented more prominently.
If a non-letter is at the start of a word, it is sorted
in front of letters. If it is inmidst a word, it is
sorted at the end. Is this intended? Is this wanted by
our users?
It might be that non-letters at the start are put into
letter group "default" and that the order of letter
groups output is determined by
define-lettergroups and not by sort order. This would
mean that we have always a difference between sort
order and letter group order.
First, check if there is always the difference.
If yes, document it; and we're done.
If not, make a survey what the users want, and/or what
standards say.