def index_data_descriptive(self):
        '''Descriptive data to be included in :meth:`index_data`
        output.  This implementation includes all Dublin Core fields,
        but should be extended or overridden as appropriate for custom
        :class:`~eulfedora.models.DigitalObject` classes.'''

        dc_fields = ['title', 'contributor', 'coverage', 'creator', 'date', 'description',
                     'format', 'identifier', 'language', 'publisher', 'relation',
                     'rights', 'source', 'subject', 'type']
        dc_data = {}
        for field in dc_fields:
            list_field = getattr(self.dc.content, '%s_list' % field)
            if list_field:
                # convert xmlmap lists to straight lists so simplejson can handle them
                dc_data[field] = list(list_field)
        return dc_data