Gold Ring - 14kpa9

[TonyHollee]

I just bought a ring that has 14kpa9 stamped on the inside. I found out what the KP is; karat plumb, but what does the A9 signify?

Thanks in advance.

 

[Modified Brilliant]

Could be an identifying quality code from the manufacturer. Oftentimes used to identify a range of diamond quality for example. Also helps the salesperson. Just my guess.