stars on a automag valve?

I always see people ask " how many stars left"
?? What do the stars on the valve mean ???

Used to be for some sort of rebuild program. A star would be polished off after a rebuild. When all the stars were gone it was out of warranty. At least that's how I understood it. It's no longer an active program.

Star program was early 2000s era. Guns made before that did not have any stars.

Everything opbn said is correct.