code: function(value, element) {
             var html = [],
                 checked = $.fn.editableutils.itemsByValue(value, this.sourceData);
                 
             if(checked.length) {
                 $.each(checked, function(i, v) { html.push($.fn.editableutils.escape(v.text)); });
                 $(element).html(html.join('<br>'));
             } else {
                 $(element).empty(); 
             }
          }
docs: collect text of checked boxes