(a) Liquor and tobacco. Subpart M applies to:

(1) Duty-free and tax-free liquor and tobacco; and

(2) Duty-paid and tax-paid liquor and tobacco which has been placed in the same liquor kit as duty-free and tax-free liquor and tobacco.

(b) Aircraft. Subpart M applies to all commercial aircraft on domestic or foreign flights operating into, from and between U.S. airports, which are carrying:

(1) Duty-free and tax-free liquor and tobacco withdrawn from bond under section 309, Tariff Act of 1930, as amended (19 U.S.C. 1309); or

(2) Other liquor or tobacco on which duty or taxes have not been paid.