Glossary
The model identifier stamped or printed on a watch, describing the specific configuration of case, dial, and materials for that model.
A reference number should be internally consistent with everything else on the watch: the case material, dial color, bezel type, and bracelet all follow from what that reference is documented to be. Authenticators check whether a stated reference matches what the physical watch actually shows, since a mismatch, or a reference number that doesn't exist at all, is one of the fastest ways to catch a misdescribed watch.
Browse the full glossary, or look up a serial number in the registry.