SELECT document_type_code ,  document_type_name ,  document_type_description FROM Ref_document_types
Show all document type codes, document type names, document type descriptions.
SELECT document_type_code , document_type_name , document_type_description FROM Ref_document_types
select document_type_code , document_type_name , document_type_description from ref_document_types
Show all document type codes , document type names , document type descriptions .