In reply to Mark Perkins.

All Rolex markings have meanings (both on the bracelet and the watch itself). These can indicate the date it was produced, its style, materials, etc. - In many instances, the markings on the clasp denote material and production year, although it is important to remember that after 2011, Rolex switched to a random serial number system.

Here is a link to our resource page where you can learn a bit more about these markings and their meanings.