code: static void addEditDirective(Element plfNode, String attributeName, IPerson person)
              throws PortalException {
          addDirective(plfNode, attributeName, Constants.ELM_EDIT, person);
      }
docs: Create and append an edit directive to the edit set if not there. This only records that the
  attribute was changed and the value in the plf copy node should be used, if allowed, during
  the merge at login time.