Task: Text to Code
Input (English): Step 1: find the Template_Type_Code of Ref_Template_Types table.
Step 2: find the Template_Type_Code of Templates table.
Step 3: show the rows that are in the results of step 1 but not in the results of step 2
Output (English): SELECT T1.Template_Type_Code FROM Ref_Template_Types AS T1 EXCEPT SELECT T2.Template_Type_Code FROM Templates AS T2