The ident number lasered onto the clip, or onto the cap ring, works rather like a vehicle's chassis number: it belongs permanently to one particular pen, and the manufacturer can use it to establish when that pen was made and which country it was shipped to. The code cannot be decoded from outside, however. There is no publicly known system from which the year, the model line or the country of sale could be read off directly.
If you want the production date, quote the full number to customer service; they will usually give you the month and year of manufacture. Enquiries of this kind have shown that an outsider can infer no order at all from the groups of letters and digits: pens with entirely unrelated number ranges turned out to have been bought in the same country, while the production dates returned were years apart. Dating by way of the number is therefore only possible with the manufacturer's help; the absence of a number, on the other hand, is entirely normal on older pens.