diff --git a/src/main/java/org/gcube/gcat/api/GCatConstants.java b/src/main/java/org/gcube/gcat/api/GCatConstants.java
index a334e70..9f3d743 100644
--- a/src/main/java/org/gcube/gcat/api/GCatConstants.java
+++ b/src/main/java/org/gcube/gcat/api/GCatConstants.java
@@ -10,8 +10,12 @@ public class GCatConstants {
 	public static final String APPLICATION_JSON_CHARSET_UTF_8 = "application/json;charset=UTF-8";
 	public static final String LIMIT_PARAMETER = "limit";
 	public static final String OFFSET_PARAMETER = "offset";
-	public static final String ORGANIZATION_PARAMETER = "org";
+	
+	public static final String ORGANIZATION_PARAMETER = "organization";
+	public static final String Q_KEY = "q";
 	
 	public static final String SOCIAL_POST_PARAMETER = "social_post";
+
+	public static final String ORGANIZATION_FILTER_TEMPLATE = ORGANIZATION_PARAMETER + ":%s";
 	
 }
diff --git a/src/main/java/org/gcube/gcat/api/interfaces/Item.java b/src/main/java/org/gcube/gcat/api/interfaces/Item.java
index 28dc2e5..57a245e 100644
--- a/src/main/java/org/gcube/gcat/api/interfaces/Item.java
+++ b/src/main/java/org/gcube/gcat/api/interfaces/Item.java
@@ -1,5 +1,7 @@
 package org.gcube.gcat.api.interfaces;
 
+import java.util.Map;
+
 import javax.xml.ws.WebServiceException;
 
 /**
@@ -9,6 +11,8 @@ public interface Item<C,D> extends CRUD<C,D> {
 	
 	String ITEMS = "items";
 
+	public String list(Map<String,String> parameters) throws WebServiceException;
+	
 	public String list(int limit, int offset) throws WebServiceException;
 	
 	public D delete(String name, boolean purge) throws WebServiceException;