I'm going to go out on a limb and venture a guess here, Rob; pots are one of the few things Alembic doesn't make in-house, & I think the codes are put there by the manufacturer. Alembic, if I'm not mistaken, uses Bourns, which I am not really familiar with, but on CTS and such like, they're stamped into the metal at the CTS or whomever factory; that's the date the pot was made, not the instrument.
Peter