diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java
index 7acc021b4..5c3a4c37c 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java
@@ -91,16 +91,14 @@ public class IdentifierFactory implements Serializable {
 		if (CleaningFunctions.PID_BLACKLIST.contains(StringUtils.trim(s.getValue().toLowerCase()))) {
 			return false;
 		}
-		try {
-			switch (PidType.valueOf(s.getQualifier().getClassid())) {
-				case doi:
-					final String doi = StringUtils.trim(StringUtils.lowerCase(s.getValue()));
-					return doi.matches(DOI_REGEX);
-				default:
-					return true;
-			}
-		} catch (IllegalArgumentException e) {
-			return false;
+		switch (PidType.tryValueOf(s.getQualifier().getClassid())) {
+			case doi:
+				final String doi = StringUtils.trim(StringUtils.lowerCase(s.getValue()));
+				return doi.matches(DOI_REGEX);
+			case original:
+				return false;
+			default:
+				return true;
 		}
 	}
 
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/OrganizationPidComparator.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/OrganizationPidComparator.java
index 8cca517f9..57285fb82 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/OrganizationPidComparator.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/OrganizationPidComparator.java
@@ -10,8 +10,8 @@ public class OrganizationPidComparator implements Comparator<StructuredProperty>
 	@Override
 	public int compare(StructuredProperty left, StructuredProperty right) {
 
-		PidType lClass = PidType.valueOf(left.getQualifier().getClassid());
-		PidType rClass = PidType.valueOf(right.getQualifier().getClassid());
+		PidType lClass = PidType.tryValueOf(left.getQualifier().getClassid());
+		PidType rClass = PidType.tryValueOf(right.getQualifier().getClassid());
 
 		if (lClass.equals(PidType.GRID))
 			return -1;
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidType.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidType.java
index 9a0196ccc..62f682026 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidType.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidType.java
@@ -6,7 +6,7 @@ import org.apache.commons.lang3.EnumUtils;
 public enum PidType {
 
 	// Result
-	doi, pmid, pmc, handle, arXiv, NCID, GBIF, nct, pdb,
+	doi, pmid, pmc, handle, arXiv, nct, pdb,
 
 	// Organization
 	GRID, mag_id, urn,
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ResultPidComparator.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ResultPidComparator.java
index 38c7743a2..e51c4801f 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ResultPidComparator.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/ResultPidComparator.java
@@ -10,8 +10,8 @@ public class ResultPidComparator implements Comparator<StructuredProperty> {
 	@Override
 	public int compare(StructuredProperty left, StructuredProperty right) {
 
-		PidType lClass = PidType.valueOf(left.getQualifier().getClassid());
-		PidType rClass = PidType.valueOf(right.getQualifier().getClassid());
+		PidType lClass = PidType.tryValueOf(left.getQualifier().getClassid());
+		PidType rClass = PidType.tryValueOf(right.getQualifier().getClassid());
 
 		if (lClass.equals(PidType.doi))
 			return -1;
@@ -38,24 +38,14 @@ public class ResultPidComparator implements Comparator<StructuredProperty> {
 		if (rClass.equals(PidType.arXiv))
 			return 1;
 
-		if (lClass.equals(PidType.NCID))
-			return -1;
-		if (rClass.equals(PidType.NCID))
-			return 1;
-
-		if (lClass.equals(PidType.GBIF))
-			return -1;
-		if (rClass.equals(PidType.GBIF))
-			return 1;
-
 		if (lClass.equals(PidType.nct))
 			return -1;
 		if (rClass.equals(PidType.nct))
 			return 1;
 
-		if (lClass.equals(PidType.urn))
+		if (lClass.equals(PidType.pdb))
 			return -1;
-		if (rClass.equals(PidType.urn))
+		if (rClass.equals(PidType.pdb))
 			return 1;
 
 		return 0;