I'm sure others will chime in but since 2003 or thereabouts, codes have been essentially undecipherable. With the leveling out of quality in production these last 2 years, some regard the information that codes entail to have become superfluous.
The only circumstances where one can link a code to a factory is if someone was in the boxing area and saw cigars of a certain marca and vitola going into a stamped box. As you might imagine, these opportunities are rare.
What is more important that the actual letters used is the appearance of the letters and the font. Of course, "knowing your vendor" is the best defense against authenticity issues, but a little knowledge can be a useful thing (if used judiciously).
Wilkey