diff --git a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/IEncapsulatedOpenBISService.java b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/IEncapsulatedOpenBISService.java
index ec7e656044639763392984d374a72c652e38a89b..036b5d5b7d64bf766a4b961e22bc10da40efb71d 100644
--- a/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/IEncapsulatedOpenBISService.java
+++ b/datastore_server/source/java/ch/systemsx/cisd/openbis/dss/generic/shared/IEncapsulatedOpenBISService.java
@@ -344,7 +344,7 @@ public interface IEncapsulatedOpenBISService extends IEncapsulatedBasicOpenBISSe
             Date maxDeletionDateOrNull);
 
     /**
-     * Updates specified properties of given data set.
+     * Updates specified properties of given data set. It only adds new properties and don't update existing ones.
      */
     @ManagedAuthentication
     public void updateDataSet(String code, List<NewProperty> properties, SpaceIdentifier space)