code: function (collection, settings, html, oldIndex, newIndex, oldKey, newKey) {
              var toReplace = new RegExp(pregQuote(settings.name_prefix + '[' + oldKey + ']'), 'g');
              var replaceWith = settings.name_prefix + '[' + newKey + ']';
              html = html.replace(toReplace, replaceWith);
  
              toReplace = new RegExp(pregQuote(collection.attr('id') + '_' + oldIndex), 'g');
              replaceWith = collection.attr('id') + '_' + newIndex;
              html = html.replace(toReplace, replaceWith);
  
              return html;
          }
docs: same as above, but will replace element names and indexes in an html string instead of in a dom element.