37 CFR § 5.12 - Petition for license.
(a) Filing of an application in the United States Patent and Trademark Office on an invention made in the United States will be considered to include a petition for license under 35 U.S.C. 184 for the subject matter of the application. The filing receipt or other official notice will indicate if a license is granted. If the initial automatic petition is not granted, a subsequent petition may be filed under paragraph (b) of this section.
(b) A petition for license must include the fee set forth in § 1.17(g) of this chapter, the petitioner's address, and full instructions for delivery of the requested license when it is to be delivered to other than the petitioner. The petition should be presented in letter form.