LV date codes ran from 1982 to March 2021, and the rules changed three times: digits only in the early 1980s, factory letters added mid-decade, letters moved to the front in 1990 with a month-and-year cipher, and the same cipher switched from month to WEEK in 2007. Misapplying the month formula to a post-2007 code is the standard mistake; this decoder applies the right rule for the era, names the factory country, and checks the date against the selected model's documented history.
The code dates and places the bag; it authenticates nothing, and counterfeits carry correct-format codes. Three checks turn the date into doctrine: the factory letters must match the made-in stamp (a contradiction is definitive), the code's era must match the canvas, lining and hardware, and the date cannot predate the model. Bags before 1982 carry no code at all, and absence on true vintage is normal, as it is on post-March-2021 bags, which carry microchips instead (some small accessories kept printed codes after the switch). Factory letters are released over time and a handful serve two countries, so an unlisted code is a flag for closer inspection, not a verdict by itself.