diff --git a/pom.xml b/pom.xml
index 666f465..62959a7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
     <groupId>eu.dnetlib.dhp</groupId>
     <artifactId>dhp-schemas</artifactId>
     <packaging>jar</packaging>
-    <version>2.10.31-SNAPSHOT</version>
+    <version>2.10.30-SNAPSHOT</version>
 
 
     <licenses>
@@ -33,7 +33,7 @@
         <connection>scm:git:gitea@code-repo.d4science.org:D-Net/dhp-schemas.git</connection>
         <developerConnection>scm:git:gitea@code-repo.d4science.org:D-Net/dhp-schemas.git</developerConnection>
         <url>https://code-repo.d4science.org/D-Net/dhp-schemas/</url>
-        <tag>dhp-schemas-2.10.25</tag>
+        <tag>dhp-schemas-2.10.30</tag>
     </scm>
 
     <description>This module contains common schema classes meant to be used across the dnet-hadoop submodules</description>
diff --git a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
index 1ce1a73..1f32c33 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
@@ -57,8 +57,10 @@ public class ModelConstants {
 	public static final String DNET_RELATION_SUBRELTYPE = "dnet:relation_subRelType";
 	public static final String DNET_RELATION_RELCLASS = "dnet:relation_relClass";
 
-	public static final String PEER_REVIEWED = "nonPeerReviewed";
-	public static final String NON_PEER_REVIEWED = "nonPeerReviewed";
+	public static final String PEER_REVIEWED_CLASSNAME = "nonPeerReviewed";
+	public static final String NON_PEER_REVIEWED_CLASSNAME = "nonPeerReviewed";
+	public static final String PEER_REVIEWED_CLASSID = "0001";
+	public static final String NON_PEER_REVIEWED_CLASSID = "0002";
 
 	public static final String SYSIMPORT_CROSSWALK_REPOSITORY = "sysimport:crosswalk:repository";
 	public static final String SYSIMPORT_CROSSWALK_ENTITYREGISTRY = "sysimport:crosswalk:entityregistry";
diff --git a/src/main/java/eu/dnetlib/dhp/schema/common/RefereedComparator.java b/src/main/java/eu/dnetlib/dhp/schema/common/RefereedComparator.java
index 3c962ce..86c0d97 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/common/RefereedComparator.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/common/RefereedComparator.java
@@ -1,10 +1,10 @@
 
 package eu.dnetlib.dhp.schema.common;
 
-import eu.dnetlib.dhp.schema.oaf.Qualifier;
-
 import java.util.Comparator;
 
+import eu.dnetlib.dhp.schema.oaf.Qualifier;
+
 public class RefereedComparator implements Comparator<Qualifier> {
 
 	@Override
@@ -23,14 +23,14 @@ public class RefereedComparator implements Comparator<Qualifier> {
 		if (lClass.equals(rClass))
 			return 0;
 
-		if (lClass.equals(ModelConstants.PEER_REVIEWED))
+		if (lClass.equals(ModelConstants.PEER_REVIEWED_CLASSID))
 			return -1;
-		if (rClass.equals(ModelConstants.PEER_REVIEWED))
+		if (rClass.equals(ModelConstants.PEER_REVIEWED_CLASSID))
 			return 1;
 
-		if (lClass.equals(ModelConstants.NON_PEER_REVIEWED))
+		if (lClass.equals(ModelConstants.NON_PEER_REVIEWED_CLASSID))
 			return -1;
-		if (rClass.equals(ModelConstants.NON_PEER_REVIEWED))
+		if (rClass.equals(ModelConstants.NON_PEER_REVIEWED_CLASSID))
 			return 1;
 
 		if (lClass.equals(ModelConstants.UNKNOWN))