docs: def identifier_director(**kwargs):
      """Direct how to handle the identifier element."""
      ark = kwargs.get('ark', None)
      qualifier = kwargs.get('qualifier', None)
      content = kwargs.get('content', '')
  
      # See if the ark and domain name were given.
      if ark:
          content = 'http://digital.library.unt.edu/%s' % ark
      elif qualifier:
          content = '%s: %s' % (qualifier, content)
      return ETD_MSIdentifier(content=content)