Yes, the distillery is usually helpful when you write them. I have never written to a distillery in part because I never thought that it would do much good!
With the rise in price comes a rise in counterfeit bottles placed on the market by unscrupulous people.I believe the precise codes will vary from company to company.Don't you love it when someone answers a question here with a bunch of folderol that amounts to "heck if I know"?I think in that case there will be no one answer, as the markings bottlers use will have changed many times over the years. I really can’t help you out with all bottlings but remember this one concerning Ardbeg/Glenmorangie!
The following is from Leither posted in Q&A: “Uigeadail” and dated Sept 22, 2006!
Anyway, my Uigeadails (all unopened, 1 finished which was one of the best bottles of whisky ever) are as follows: L4 068 4ML - this one says 'BOTTLED IN THE YEAR 2004' on the back label and refers to 'a special vatting of 1993... Well I have gotten some good advise but this peticular bottle of Cutty Sark is completely nake other than the US ATF TAX Stamp that hasn't been used for nearly 20 or so years from what I have been told. He/She should try the word association thread on Whisky Chat...