Large packaging code designations consist of: two numerals specified in paragraph (a) of this section; followed by the capital letter(s) specified in paragraph (b) of this section.
(a) Large packaging code number designations are as follows: 50 for rigid Large Packagings; or 51 for flexible Large Packagings.
(b) Large Packagings code letter designations are as follows:
(1) ``A'' means steel (all types and surface treatments).
(2) ``B'' means aluminum.
(3) ``C'' means natural wood.
(4) ``D'' means plywood.
(5) ``F'' means reconstituted wood.
(6) ``G'' means fiberboard.
(7) ``H'' means plastic.
(8) ``M'' means paper, multiwall.
(9) ``N'' means metal (other than steel or aluminum).