diff --git a/src/main/java/org/gcube/gcat/api/GCatConstants.java b/src/main/java/org/gcube/gcat/api/GCatConstants.java
index ed2b7f8..cbbb6e0 100644
--- a/src/main/java/org/gcube/gcat/api/GCatConstants.java
+++ b/src/main/java/org/gcube/gcat/api/GCatConstants.java
@@ -21,8 +21,10 @@ public class GCatConstants {
 	public static final String Q_KEY = "q";
 	
 	public static final String SOCIAL_POST_QUERY_PARAMETER = "social_post";
+	public static final String SOCIAL_POST_NOTIFICATION_QUERY_PARAMETER = "social_post_notification";
+	
+	public static final String REFER_ONLY_RESOURCE_QUERY_PARAMETER = "refers_only";
 	
-
 	public static final String ORGANIZATION_FILTER_TEMPLATE = ORGANIZATION_PARAMETER + ":%s";
 	
 	public static final String CATALOGUE_MEMBER = "Catalogue-Member";