Frame Markings on a Model 36

[Vettepartz]

Other than the assembly number, does anyone know what these frame markings are on a Model 36?

 

[stansdds]

They are assembly markings and the meanings are known only to S&W.

 

[JP@AK]

The 5 and the Y are inspector's stamps.

 

[Vettepartz]

I don't know if that is a "Y" or what. It looks like one of the pictures I saw in sex education class when I was in high school.