Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Ref_template_types (template_type_description VARCHAR, template_type_code VARCHAR)

### Question ###
What is the template type descriptions for template type code "AD".

### Accurate SQL ###

SELECT template_type_description FROM Ref_template_types WHERE template_type_code = "AD"