904.01(b) In Combined or Multiple-Class Applications
A combined (or multiple-class) application is a request to register the same mark for goods and/or services in multiple classes in a single application. There must be one specimen of the mark for each class. 15 U.S.C. §1051(a)(1); 37 C.F.R. §§2.34(a)(1)(iv) and 2.56(a). If a single specimen supports multiple classes, the applicant should indicate which classes are supported by the specimen. The examining attorney need not require multiple copies of the specimen. The examining attorney should enter a Note to the File in the record indicating which classes the specimen supports.
See TMEP §§1403 et seq. regarding examination of multiple-class applications.