diff --git a/src/main/java/org/gcube/informationsystem/base/reference/IdentifiableElement.java b/src/main/java/org/gcube/informationsystem/base/reference/IdentifiableElement.java
index 6533b00..0557fbd 100644
--- a/src/main/java/org/gcube/informationsystem/base/reference/IdentifiableElement.java
+++ b/src/main/java/org/gcube/informationsystem/base/reference/IdentifiableElement.java
@@ -11,7 +11,7 @@ import org.gcube.informationsystem.model.reference.properties.Metadata;
  */
 public interface IdentifiableElement extends Element {
 	
-	public static final String UUID_PROPERTY = "@uuid";
+	public static final String UUID_PROPERTY = "uuid";
 	public static final String METADATA_PROPERTY = "@metadata";
 	
 	public UUID getUUID();
diff --git a/src/test/java/org/gcube/informationsystem/model/impl/properties/PropagationConstraintTest.java b/src/test/java/org/gcube/informationsystem/model/impl/properties/PropagationConstraintTest.java
index 5e8500b..389ceb6 100644
--- a/src/test/java/org/gcube/informationsystem/model/impl/properties/PropagationConstraintTest.java
+++ b/src/test/java/org/gcube/informationsystem/model/impl/properties/PropagationConstraintTest.java
@@ -3,6 +3,7 @@ package org.gcube.informationsystem.model.impl.properties;
 import java.util.Calendar;
 
 import org.gcube.informationsystem.base.reference.Element;
+import org.gcube.informationsystem.base.reference.IdentifiableElement;
 import org.gcube.informationsystem.model.reference.entities.Facet;
 import org.gcube.informationsystem.model.reference.entities.Resource;
 import org.gcube.informationsystem.model.reference.properties.PropagationConstraint;
@@ -129,15 +130,15 @@ public class PropagationConstraintTest {
 			"\"" + ConsistsOf.PROPAGATION_CONSTRAINT_PROPERTY + "\":"+ pcString + "," +
 			"\"" + ConsistsOf.METADATA_PROPERTY + "\": " + hString + "," +
 			"\"" + ConsistsOf.SOURCE_PROPERTY + "\":{" +
-				"\"@uuid\":\"4a971915-ca90-48cf-9975-63ee2dd28605\"," +
-				"\"@class\":\"MyEService\"," +
-				"\"@superClasses\":[\"EService\", \"Service\", \"Resource\"]," +
+				"\"" + IdentifiableElement.UUID_PROPERTY + "\":\"4a971915-ca90-48cf-9975-63ee2dd28605\"," +
+				"\"" + Element.CLASS_PROPERTY + "\":\"MyEService\"," +
+				"\"" + Element.SUPERCLASSES_PROPERTY + "\":[\"EService\", \"Service\", \"Resource\"]," +
 				"\"" + ConsistsOf.METADATA_PROPERTY + "\": " + hString +
 				"}," +
 			"\"" + ConsistsOf.TARGET_PROPERTY + "\":{" +
-				"\"@uuid\":\"3ace4bd0-e5cd-49a3-97a8-a0a9468ce6d4\"," +
-				"\"@class\":\"MySoftwareFacet\"," +
-				"\"@superClasses\":[\"SoftwareFacet\", \"Facet\"]," +
+				"\"" + IdentifiableElement.UUID_PROPERTY + "\":\"3ace4bd0-e5cd-49a3-97a8-a0a9468ce6d4\"," +
+				"\"" + Element.CLASS_PROPERTY + "\":\"MySoftwareFacet\"," +
+				"\"" + Element.SUPERCLASSES_PROPERTY + "\":[\"SoftwareFacet\", \"Facet\"]," +
 				"\"" + ConsistsOf.METADATA_PROPERTY + "\": " + hString + "," + 
 				"\"name\":\"WhnManager\"," +
 				"\"group\":\"VREManagement\"," +