I needed a way to get an empty attribute in to the current document.
Policy seems pretty much designed to prevent this from happening. So,
working around it:

<description>Handle Missing Middle Initials</description>
<if-op-attr name="Initials" op="not-available"/>
<do-add-dest-attr-value name="Initials">
<token-local-variable name="Null"/>

David Gersic dgersic_@_niu.edu

I'm tired of receiving rubbish in my mailbox, so the E-mail address is
munged to foil the junkmail bots. Humans will figure it out on their own.