37 CFR 1.1002: The United States Patent and Trademark Office as an office of indirect filing.

(a) The United States Patent and Trademark Office, as an office of indirect filing, shall accept international design applications where the applicant's Contracting Party is the United States.

(b) The major functions of the United States Patent and Trademark Office as an office of indirect filing include:

(1) Receiving and according a receipt date to international design applications;

(2) Collecting and, when required, transmitting fees due for processing international design applications;

(3) Determining compliance with applicable requirements of part 5 of this chapter; and

(4) Transmitting an international design application to the International Bureau, unless prescriptions concerning national security prevent the application from being transmitted.