Reltio Connect

I have created an RDM lookup type and mapped it to an attribute.

However, the source system sometimes sends the attribute value as blank, empty (""), or null. When such records are loaded, the entity shows the following warning:

Lookup resolving error: 1003: RDM canonical value mapping not found for value [].

I tried creating an empty string or blank value mapping in RDM, but RDM does not allow creating a canonical value for an empty or null value.

How can this warning be resolved? Is there a recommended approach to handle blank or null values for lookup attributes in Reltio RDM?

Best would be to assign a defualt NOVALUE in the ETL layer. Show it as no value in Reltio by creating a mapping for NOVALUE from source.