diff --git a/fr.centralesupelec.edf.riseclipse.iec61850.nsd/src/fr/centralesupelec/edf/riseclipse/iec61850/nsd/util/NsIdentification.java b/fr.centralesupelec.edf.riseclipse.iec61850.nsd/src/fr/centralesupelec/edf/riseclipse/iec61850/nsd/util/NsIdentification.java
index 651ad96ebd803b6e892a7f8d12acbb2a8315c08d..5419d5f6a326958872c010723b09f4853facd342 100644
--- a/fr.centralesupelec.edf.riseclipse.iec61850.nsd/src/fr/centralesupelec/edf/riseclipse/iec61850/nsd/util/NsIdentification.java
+++ b/fr.centralesupelec.edf.riseclipse.iec61850.nsd/src/fr/centralesupelec/edf/riseclipse/iec61850/nsd/util/NsIdentification.java
@@ -47,7 +47,8 @@ public class NsIdentification {
 
     @Override
     public int hashCode() {
-        return Objects.hash( id, release, revision, version );
+        // Only id and version are required, revision and release are optional
+        return Objects.hash( id, version );
     }
 
     @Override
@@ -56,8 +57,7 @@ public class NsIdentification {
         if( obj == null ) return false;
         if( getClass() != obj.getClass() ) return false;
         NsIdentification other = ( NsIdentification ) obj;
-        return Objects.equals( id, other.id ) && Objects.equals( release, other.release )
-                && Objects.equals( revision, other.revision ) && Objects.equals( version, other.version );
+        return Objects.equals( id, other.id ) && Objects.equals( version, other.version );
     }
 
     @Override
@@ -68,4 +68,5 @@ public class NsIdentification {
                 + ( release != null ? "release=" + release : "" ) + "]";
     }
 
-}
\ No newline at end of file
+}
+