Last year I had a very minor problem with a D'Addario string and their customer service department went WAY beyond what they needed to do to fix the problem. Thanks again D'Addario! In my discussion with their rep, he asked me for the code number on the package. I gave him the code #6C3G1. He said that dated the strings March of 2006. That would mean the first number is the year and presumably C or the number 3 would be the month of manufacture. Does anybody know what date code pattern is correct, and is it used for all of their strings?