Mandelbaum’s right, but only to an extent. While saying “Rolex 1675” might feel like a specific watch, it can still conjure up a different image for different people. Sure, it’s a vintage GMT-Master, but is it steel or gold? Gilt or matte dial? What about the bezel? On a strap or bracelet? Some of these details have only become important post-hoc – it’s hard to imagine too many people cared about pointed or square crown guards until relatively recently – but that’s also the point. The short reference number is a relic of a time when manufacturers ordered parts from their suppliers and then mixed and matched components to see what might sell. For the most part, it was people working with other people. Throughout the second half of the 20th century, computers became more involved with every single link in the supply chain, and with that squeezed the inefficiencies, human element, and maybe, some of the charm out of watchmaking.
Today, every single link of a watch’s production is perfectly orchestrated and coded into computers, often planned years in advance – from those lab-grown diamonds in the TAG Heuer Plasma to the ad you’re served up on Instagram. And reference numbers help make it all happen.