On the other hand, a serial number is an identification number that is unique to each individual watch. These digits can tell us a lot of useful information about the watch, including the model family, the case material, the bezel material and type, the bracelet material and type, and the movement type.
Some manufacturers use relatively short reference numbers (for example, Rolex and Patek Philippe) while others (such as Omega), use a long string of digits - which Omega calls a PIC number. While it's perfectly acceptable to simply say ' Omega Seamaster,' there are dozens and dozens of different versions of the watch - so reference numbers (or Omega PIC Numbers as the brand calls them now) are used for clarity. When it comes to identifying certain watch models, enthusiasts and industry insiders typically use reference numbers. Ultimate Guide to Omega Serial Numbers, Reference Numbers, and PIC Numbers
