"Right Now, each model has master useful resource arranging, and In regards to determining reference numbers, it arrives right down to what's uncomplicated and flexible to the application," TAG Heuer's Biebuyk claimed. This changeover started during the '60s and '70s as suppliers started to use rudimentary desktops and database devices. https://www.watchesworld.com/a-history-of-watch-reference-numbers/