(a) Type 21. That kind of fire-cured tobacco commonly known as Virginia Fire-cured, or Dark-fired, produced principally in the Piedmont and mountain sections of Virginia.
(b) Type 22. That type of fire-cured tobacco, known as Eastern District Fire-cured, produced principally in a section east of the Tennessee River in southern Kentucky and northern Tennessee.
(c) Type 23. That type of fire-cured tobacco, known as Western District Fire-cured or Dark-fired, produced principally in a section west of the Tennessee River in Kentucky and extending into Tennessee.
Groups applicable to types 21, 22, and 23:A--Wrappers.B--Heavy Leaf.C--Thin Leaf.X--Lugs.N--Nondescript, as defined.S--Scrap, as defined.