The current reference data is missing some grading option data. Currently many COs have the "letter" grading option value, while many COs have no value in the field. As a result, when you query Manage CO - subject code view, the CO table shows many blanks in the cells in the Grading Column.
This will not be an issue once the UMD data is implemented.
However, the Kuali Days demo will show these blank fields unless this reference data is fixed.
If this is a desired fix for Kuali Days, this needs to be prioritized by the Product Manager.