diff --git a/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java b/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
index 9254f2a..c4e0735 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
@@ -19,9 +19,8 @@ public class Relation extends Oaf implements Serializable {
         resultProject,
         resultOrganization,
         projectOrganization,
-        datasourceOrganization
-
-        //TODO organizationOrganization ????
+        datasourceOrganization,
+        organizationOrganization;
     }
 
     public enum SUBRELTYPE {
@@ -97,6 +96,7 @@ public class Relation extends Oaf implements Serializable {
         Obsoletes,
         Reviews,
         isSimilarTo,
+        isDifferentFrom,
         produces;
 
         public static boolean exists(String relclass) {
@@ -119,6 +119,7 @@ public class Relation extends Oaf implements Serializable {
                 case isMergedIn:
                 case merges:
                 case isSimilarTo:
+                case isDifferentFrom:
                     return SUBRELTYPE.dedup;
                 case isProducedBy:
                 case produces:
@@ -180,7 +181,7 @@ public class Relation extends Oaf implements Serializable {
         /**
          * This mehtod is an implementation of the valueOF case insensitive
          * @param value the input Value
-         * @return the RELCLASS 
+         * @return the RELCLASS
          */
         public static RELCLASS lookUp(String value) {
             Optional<RELCLASS> rvlaue = Arrays.stream(RELCLASS.values()).filter(e -> e.name().equalsIgnoreCase(value)).findAny();
@@ -288,6 +289,10 @@ public class Relation extends Oaf implements Serializable {
                     return IsReviewedBy;
                 case produces:
                     return isProducedBy;
+                case isSimilarTo:
+                    return isSimilarTo;
+                case isDifferentFrom:
+                    return isDifferentFrom;
             }
             // makes the compiler happy
             throw new IllegalArgumentException("missing inverse mapping for" + this);