What does the Citizen article number mean?

The model number can be found on the box or warranty certificate of your Citizen items.
Numbers and letters are engraved on the back of the Citizen watch. These stand for the manufacturer, water resistance according to DIN8310, housing material, work number + case number, serial number, housing structure and the country of origin.

The second letter is ongoing. The first three numbers of the four-digit digit are continuous, only the last number describes the color of the case.