question

[gt53]

What does the m and g and all these letters on rolex watches mean?

[GradyPhilpott]

Are you speaking of the serial or random identifying numbers?

If so, before the random identifiers, a series letter was applied to a serial number, I would assume to extend the usefulness of the serial number system beyond what a number-only system would be.

The "random" insertion of letters into the random identifier, would extend the series, although random, even further.

I hope this helps and if I'm wrong someone will be along later to help.

[jekuo]

With the old letter system, you could estimate the production year of a certain watch by the letter in the first position of the serial number. That's why you still see references to a watch being an M, G, or V etc. series. But Rolex changed that by going to its current random serial number system so that it is near impossible for the typical hobbyist to know a watch's production year by just looking at the serial number.