(b) Package identification number. A package identification number shall apply to all of the packages filled at the same time on which all of the marks required by § 20.178 (a)(1) and (a)(3) through (a)(8) are identical. All of the packages in one lot shall be the same type, have the same rated capacity, and be uniformly filled with the same quantity. A package identification number shall be derived from the date on which the package is filled, and shall consist of the following elements, in the order shown—

1. (1) The last two digits of the calendar year;
2. (2) An alphabetical designation from “A” through “L,” representing January through December, in that order;
3. (3) The digits corresponding to the day of the month; and
4. (4) A letter suffix when more than one identical lot is filled into packages during the same day. For successive lots after the first lot, a letter suffix shall be added in alphabetical order, with “A” representing the second lot of the day, “B” representing the third lot of the day, etc. (e.g., the first three lots filled into packages on November 19, 1983, would be identified as “83K19,” “83K19A,” and “83K19B”).

(d) Continuation of numbering series. If a change in proprietorship, name, or trade name occurs, the numbering system in use at the time of the change may be continued. If serial numbers are used at the time of a change, the numbering series in use at the time of the change may be continued.

(Sec. 201, Pub. L. 85-859, 72 Stat. 1360, as amended (26 U.S.C. 5206))