Annoying case one: hyphenated given names. If you break them up into multiple <namePart> elements, where does the hyphen go?
<mads ID="chang.f-l.f">
        <authority>
                <name type="personal">
                        <namePart type="family">Chang</namePart>
                        <namePart type="given">F.-L. F.</namePart>
                </name>
        </authority>
</mads>

Annoyng case two: Ideographic names that are a single character.
<mads ID="kamegaki.h">
        <authority>
                <name type="personal">
                        <namePart type="family"> 垣</namePart>
                        <namePart type="given">一</namePart>
                </name>
        </authority>
        <refs>
                <ref variantType="translation">
                        <name transliteration="iso3602">
                                <namePart type="family">kamegaki</namePart>
                                <namePart type="given">hazime</namePart>
                        </name>
                </ref>
        </refs>
        <note type="sort order">カメガキ ハジメ</note>
</mads>

Annoying case three (no example because it's not something you can see): the initial is a base character followed by one or more combining characters.

Annoying case four (I had an example but couldn't find it): the name is a single Latin letter.

Annoying case five: the former name of the artist currently known as Prince (all right, we can just ignore this one).

>>> [log in to unmask] 2004-06-11 10:33:43 >>>
OK, I was playing with a solution to initialized names earlier. Logic
is:

All given names have their own nameParts.
If such namePart only contains one character, it is understood to be
initialized.
If not, it is not initialized.

Is that generalizable?

Bruce