Exercise: Convince a toff the hyphen in his name is just a display
convention. :)

But here's a better example than in my original post:

<mads ID="merzenich.m.m">
        <authority>
                <name type="personal">
                        <namePart type="family">Merzenich</namePart>
                        <namePart type="given">Michael M.</namePart>
                </name>
        </authority>
</mads>
<mads ID="mesulam.m.m">
        <authority>
                <name type="personal">
                        <namePart type="family">Mesulam</namePart>
                        <namePart type="given">Marek-Marsel</namePart>
                </name>
        </authority>
</mads>

In a list of references the first might appear as "Merzenich, M. M." or
"Merzenich MM" or one of a few other possibilities, but never as
"Merzenich M-M" or "Merzenich M.-M." The second person's name can be
(and often is) written as "Mesulam M-M" or "Mesulam M.-M." If you
have...
<mads ID="mesulam.m.m">
        <authority>
                <name type="personal">
                        <namePart type="family">Mesulam</namePart>
                        <namePart type="given">Marek</namePart>
                        <namePart type="given">Marsel</namePart>
                </name>
        </authority>
</mads>
...no stylesheet is going to be able to figure out there's supposed to
be a hyphen in there somewhere.

>>> [log in to unmask] 2004-06-11 11:09:17 >>>
> From: Andrew E Switala [mailto:[log in to unmask]]
> Sent: 11 June, 2004 10:55
> Subject: Re: [MODS] names and abbreviation
>
> Annoying case one: hyphenated given names. If you break them
> up into multiple <namePart> elements, where does the hyphen go?

It doesn't. The hyphen is a display convention. Keep markup
and content separate. The display rules may say to for each
name part after the first, add a hyphen, before concatenating
the name part. Or other display conventions may be used.