New special values are marked as undefined when saved as case in retrieval tab
Reproduce: MyCBR / Configure special values ... add a new name, close, go to CBR Retrieval on flat cars, load any car, change one of the values to the new special value and save... clear the retrieval and set the modified value to the new value again, retrieve. You would expect the new case to be most similar to your request, but it's actually ignored, as it was never saved with the new special value, but undefined instead.