(a) A letter relating to a trademark application should identify the name of the applicant, the mark, and the reference number appearing on the office action letter.(b) Each application file should be complete in itself. Although the response submitted for two or more applications may be identical, a separate response should be provided for each application.(c) A letter relating to a registered trademark should include the name of the registrant, an identification of the mark, the registration number, and the date of registration.