They are detailed reference resources with a wealth of information for helping to either establish the vintage of your guitar or bass or for just learning more about Fender history in general.
As a result, you will see some 1990 guitars bearing N9 serial numbers. Fender has recently (in the last 20 years) introduced LOTS of different serial numbers schemes, depending on the country the Fender was made (USA, Mexico, Japan, Korea, etc). The following serial numbers are somewhat outside the more, well known Fender serial number schemes.
If you have what you consider to be a somewhat "odd" serial number, please check the following chart to see if you find your serial number configuration here.
instrument production history, production dates have been applied to various components.
There were periods of time when this was not consistently done, (between 19), and there are certainly other examples of short periods of time, and individual pieces, where the dating was simply omitted.
KC and KV serial number prefixes are usually used on Crafted in Korea Squiers. It's pretty but does not sound to good when compared to the real deal.