Since the 1980s, Louis Vuitton has used date codes and serial numbers to track its products.
By this 1990s, Louis Vuitton had been manufacturing outside of France for years- through it's partnership with the US based "The French Company" (See my guide to authentic Louis Vuitton French Company pieces if you're interested). Not only that, but Louis Vuitton had a factory in Spain and soon had one of their own in San Dimas, California.
So, If I have a bag, with a date code with the CA prefix, and it has "Made in USA" or "Made in France"… I know that at the very least I need to really scruitinize that bag for authenicity. There are a few reasons why a bag could have a US date code and be Made in France… for example, if the lining has been redone… the date code may be very new (so a bag that was made in 1998 in France could end up with a 2006 date code that was repaired in the USA). It's just definitely a reason to get a second look at the bag.
Again, for whatever reason, Louis Vuitton made another change to the date code format beginning in January 2007. You will still find the same two letters followed by four number format, however instead of using the staggered month and year, Louis Vuitton is now using a staggered Week of the Year and Year formula… so that… a date code that says SD 0077 is not a bag that was made in July of 2007, but is a bag that was made in the 7th week of the year 2007- so mid-to-late February of 2007.
So how do you know what those letters mean? Here's a little guide to help you out. You'll find the country followed by the letters that coordinate with that country…
France: A0, A1, A2, AA, AAS (in special order), AN, AR, AS, BA, BJ, BU, CO, CT, DK (in repairs) DU (in special order), ET, FL, LW, MB, MI, NO, RA, RI, SD, SL, SN, SP, SR, TH, VI, VX
USA: DK (in repairs), FC, FH, LA, OS, SD, FL
Spain: CA, LO, LB, LM, LW
Italy: BC, BO, CE, FO, MA, RC, RE, SA, TD
Germany: LP
Switzerland: DI, FA