diff --git a/src/main/java/org/gcube/accounting/datamodel/aggregation/StorageStatusUsageRecord.java b/src/main/java/org/gcube/accounting/datamodel/aggregation/StorageStatusUsageRecord.java
deleted file mode 100644
index b806502..0000000
--- a/src/main/java/org/gcube/accounting/datamodel/aggregation/StorageStatusUsageRecord.java
+++ /dev/null
@@ -1,81 +0,0 @@
-/**
- * 
- */
-package org.gcube.accounting.datamodel.aggregation;
-
-import org.gcube.accounting.datamodel.BasicUsageRecord;
-/*
-import org.gcube.accounting.datamodel.validations.annotations.NotEmpty;
-import org.gcube.accounting.datamodel.validations.annotations.ValidInteger;
-import org.gcube.accounting.datamodel.validations.annotations.ValidLong;
-import org.gcube.accounting.exception.InvalidValueException;
-*/
-/**
- * This Class is for library internal use only
- * @author Luca Frosini (ISTI - CNR) http://www.lucafrosini.com/
- */
-@Deprecated
-public class StorageStatusUsageRecord extends BasicUsageRecord {
-
-	/**
-	 * Generated Serial Version UID
-	 */
-	private static final long serialVersionUID = 2456314684466092685L;
-
-	/*
-	@NotEmpty
-	public static final String PROVIDER_ID = "providerId";
-	@NotEmpty
-	public static final String QUALIFIER = "qualifier";
-	@NotEmpty
-	public static final String DATA_TYPE = "dataType";
-	@ValidLong
-	public static final String DATA_VOLUME = "dataVolume";
-	@ValidInteger
-	public static final String DATA_COUNT = "dataCount";
-	
-	public StorageStatusUsageRecord(){
-		super();
-	}
-	
-	public String getProviderId() {
-		return (String) this.resourceProperties.get(PROVIDER_ID);
-	}
-
-	public void setProviderId(String providerId) throws InvalidValueException {
-		setResourceProperty(PROVIDER_ID, providerId);
-	}
-	
-	public String getQualifier() {
-		return (String) this.resourceProperties.get(QUALIFIER);
-	}
-
-	public void setQualifier(String qualifier) throws InvalidValueException {
-		setResourceProperty(QUALIFIER, qualifier);
-	}
-	
-	public String getDataType() {
-		return (String) this.resourceProperties.get(DATA_TYPE);
-	}
-
-	public void setDataType(String dataType) throws InvalidValueException {
-		setResourceProperty(DATA_TYPE, dataType);
-	}
-	
-	public long getDataVolume() {
-		return (Long) this.resourceProperties.get(DATA_VOLUME);
-	}
-
-	public void setDataVolume(long dataVolume) throws InvalidValueException {
-		setResourceProperty(DATA_VOLUME, dataVolume);
-	}	
-	
-	public int getDataCount() {
-		return (Integer) this.resourceProperties.get(DATA_COUNT);
-	}
-
-	public void setDataCount(int dataCount) throws InvalidValueException {
-		setResourceProperty(DATA_COUNT, dataCount);
-	}
-	*/
-}
diff --git a/src/main/java/org/gcube/accounting/datamodel/aggregation/aggregationstrategy/StorageUsageRecordAggregationStrategy.java b/src/main/java/org/gcube/accounting/datamodel/aggregation/aggregationstrategy/StorageUsageRecordAggregationStrategy.java
index d5852f7..5212e7d 100644
--- a/src/main/java/org/gcube/accounting/datamodel/aggregation/aggregationstrategy/StorageUsageRecordAggregationStrategy.java
+++ b/src/main/java/org/gcube/accounting/datamodel/aggregation/aggregationstrategy/StorageUsageRecordAggregationStrategy.java
@@ -24,6 +24,7 @@ public class StorageUsageRecordAggregationStrategy extends AggregationStrategy<S
 		this.aggregationField.add(StorageUsageRecord.PROVIDER_URI);
 		this.aggregationField.add(StorageUsageRecord.OPERATION_TYPE);
 		this.aggregationField.add(StorageUsageRecord.DATA_TYPE);
+		this.aggregationField.add(StorageUsageRecord.QUALIFIER);
 	}
 
 	protected StorageUsageRecord reallyAggregate(StorageUsageRecord record)
diff --git a/src/main/java/org/gcube/accounting/datamodel/implementations/StorageUsageRecord.java b/src/main/java/org/gcube/accounting/datamodel/implementations/StorageUsageRecord.java
index 24e0eb2..6a18252 100644
--- a/src/main/java/org/gcube/accounting/datamodel/implementations/StorageUsageRecord.java
+++ b/src/main/java/org/gcube/accounting/datamodel/implementations/StorageUsageRecord.java
@@ -11,6 +11,7 @@ import org.gcube.accounting.datamodel.BasicUsageRecord;
 import org.gcube.accounting.datamodel.SingleUsageRecord;
 import org.gcube.accounting.datamodel.decorators.RequiredField;
 import org.gcube.accounting.datamodel.validations.annotations.NotEmpty;
+import org.gcube.accounting.datamodel.validations.annotations.NotEmptyIfNotNull;
 import org.gcube.accounting.datamodel.validations.annotations.ValidDataType;
 import org.gcube.accounting.datamodel.validations.annotations.ValidLong;
 import org.gcube.accounting.datamodel.validations.annotations.ValidOperationType;
@@ -96,13 +97,12 @@ public class StorageUsageRecord extends BasicUsageRecord implements SingleUsageR
 	public static final String DATA_VOLUME = "dataVolume";
 	
 	
-	/* *
+	/**
 	 * KEY for : Qualifies the data in terms of data (e.g. MIME type for the 
 	 * Storage, domain for a database)
-	 * /
+	 */
 	@NotEmptyIfNotNull
 	public static final String QUALIFIER = "qualifier";
-	*/
 	
 	public StorageUsageRecord() {
 		super();
@@ -185,7 +185,6 @@ public class StorageUsageRecord extends BasicUsageRecord implements SingleUsageR
 		setResourceProperty(DATA_VOLUME, dataVolume);
 	}
 	
-	/*
 	public String getQualifier() {
 		return (String) this.resourceProperties.get(QUALIFIER);
 	}
@@ -193,6 +192,5 @@ public class StorageUsageRecord extends BasicUsageRecord implements SingleUsageR
 	public void setQualifier(String qualifier) throws InvalidValueException {
 		setResourceProperty(QUALIFIER, qualifier);
 	}
-	*/
 	
 }