27 C.F.R. § 26.115
Application for permit to ship to the United States liquors and articles of Puerto Rican manufacture on which all taxes have been paid or deferred as prescribed in this subpart shall be made by the shipper on Form 487B, in sextuple. Each Form 487B will be given a serial number, by the applicant, beginning with "1" for the first day of January of each year and running consecutively thereafter to December 31, inclusive. This serial number will be prefixed by the last two digits of the calendar year, e.g. "61-1." All copies of the form shall be delivered to the revenue agent for execution of his certification thereon and forwarding of all copies to the Secretary within sufficient time to allow for the issuance of the permit and customs inspection as provided in § 26.116 .
27 C.F.R. § 26.115