It's an European (German) thing.
I know, but it's making headway in the USA also, especially for powder coated finishes. Years ago, I recall folks applying Pantone color numbers for paint and powder colors, but Pantone was developed for printing processes and applies more to inks, whereas I understand RAL was developed specifically for surface finishes.
I have a RAL K7 color chip booklet here at my desk for reference on powder coating and laminate surfaces. My experience is that a little squinting is required for "matching". Manufactures seem to allow themselves quite a bit of variance from the standard, while still using a RAL number to designate the finish. I could easily show you four different finishes, and all would be called RAL 9007 by their respective makers. Close enough to be "the same" in your memory, if you weren't looking at them side by side, but different enough to look motley if you tried to build an assembly from different parts coated with powder from different makers.
To get consistent appearance, we've found it's wise to get everything coated by the same vendor, using the same make and LOT number of powder.