Single-digit alphanumeric code to indicate the week of the year during which the product was manufactured.
27 base characters:
(excludes 0, AEIOU, and BSZ)
Each week is assigned a base code. Because there are more weeks in the year than base codes available, the base code repeats, but joins with the appropriate year code (above) to distinguish the overall date code.
2010, week 08 = C8
2010, week 34 = D8