sdn@sdn-build:~$ diff -u ietf-ptp-dataset@2017-04-20.yang ietf-ptp-dataset@modified.yang
--- ietf-ptp-dataset@2017-04-20.yang    2017-09-26 16:30:52.420973753 +0100
+++ ietf-ptp-dataset@modified.yang    2017-09-26 16:30:52.428977753 +0100
@@ -387,11 +387,7 @@
        description
          "Collection of members of the port data set.";

-       container port-identity {
-         description
-           "The portIdentity attribute of the local port.";
-         uses port-identity-grouping;
-       }
+       uses port-identity-grouping;

        leaf port-state {
          type port-state-enumeration;
@@ -507,12 +503,8 @@
          "Collection of members of the transparentClockPort data
           set (port data set for a transparent clock).";

-       container port-identity {
-         description
-           "The portIdentity of the local port.";
-
-         uses port-identity-grouping;
-       }
+       uses port-identity-grouping;
+
        leaf log-min-pdelay-req-interval {
          type int8;
          description
@@ -580,14 +572,7 @@
           key "port-number";
           description
             "List of port data sets of the clock.";
-          leaf port-number{
-            type leafref{
-              path "../port-identity/port-number";
-            }
-            description
-              "Refers to the portNumber memer of
-              portDS.portIdentity.";
-          }
+
           uses port-ds-entry;
         }
      }
@@ -604,14 +589,17 @@
          "List of transparentClockPort data sets
           of the transparent clock.";

-       leaf port-number {
-         type leafref {
-           path "../port-identity/port-number";
-         }
-          description
-            "Refers to the portNumber memer
-             of transparentClockPortDS.portIdentity.";
-        }