(a) The name required by the Act to be used on labels shall be the name under which the person is doing business. Where a person has a word trademark, used as a house mark, registered in the United States Patent Office, such word trademark may be used on labels in lieu of the name otherwise required. No trademark, trade names, or other names except those provided for above shall be used for required identification purposes.

(b) Registered identification numbers, as provided for in § 303.20 of this part, may be used for identification purposes in lieu of the required name.