anchor.diff:          }
       }
   
  -    function getConstructUse(grpName, constrName, use) {
  +    /**
  +     * Get the current usage setting of the construct named @constrName in group @grpName.
  +     */
  +    function getConstructUse(grpName, constrName) {
           return profile['groups'][grpName]['constructs'][constrName]['use'];
       }
   
  +    /**
  +     * jQuery handler for when the usage setting of a particular construct is changed.
  +     */
       $(".construct-usage-changer").click(function(evt) {
           evt.preventDefault(); // don't act like a link; we're handling this click
           var thisEl = $(this); // get this object as jQuery reference
  
positive.code:         $(".group-accessor").find('option:first').attr('selected', 'selected');
      });
  
      $(".field-usage-selector, .attr-usage-selector").change(function(e) { // when a field/attr usage level is changed, update the row highlighting
          var thisEl = $(this);
          var groupDiv = thisEl.closest("div[data-group-safe-name]"); // group root div with groupname info
  
negative.code:         }
      }
  
      /**
       * Set the usage info for an field named @fieldName of @constrName in group @grpName.
       * @idx is the index of the field in the list of attributes on the construct.
       */
      function setFieldUse(grpName, constrName, fieldName, idx, use) {
          var field = profile['groups'][grpName]['constructs'][constrName]['fields'][idx];
          if (field['name'] === fieldName) {
  