SolrQuery::getHighlightAlternateField Returns the highlight field to use as backup or default &reftitle.description; public stringSolrQuery::getHighlightAlternateField stringfield_override Returns the highlight field to use as backup or default. It accepts an optional override. &reftitle.parameters; field_override The name of the field &reftitle.returnvalues; Returns a string on success and &null; if not set.