(a) Certain material is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection by appointment only, during normal hours of operation, at the U.S. Postal Service Library, 475 L'Enfant Plaza West SW, Washington, DC 20260-1641 (call 202-268-2906), and is available from the sources listed below. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to www.archives.gov/federal-register/cfr/ibr-locations.html.

(b) United States Postal Service, Product Classification Office, USPS Headquarters, 475 L'Enfant Plaza SW, Room 4446, Washington, DC 20260-5013: http://pe.usps.com/text/pub52/welcome.htm.

(1) Publication 52, Hazardous, Restricted and Perishable Mail, dated August 2017, IBR approved for §113.1.

(2) [Reserved]