Mapping for Lookup Definition.Group is an error

I ran this query:

select lku_field, lku_type_string_key from lku where lku_type='f'

and lku_type_string_key like 'Lookup Definition%';

because I needed to be sure of the mapping I need in order to write the group name of a lookup using tcLookupOperationsIntf's updateLookupCode method.  I got an error tcInvalidAttributeException writing <Lookup Name  removed>: 'LKU_TYPE_GROUP' is not a valid attribute name.  My thinking is that this Field lookup needs to be mapped to LKU_GROUP not LKU_TYPE_GROUP.  There is no LKU_TYPE_GROUP in the LKU table.

Can anyone confirm my suspicions and can I just change the mapping to fix this?