French Pierrefonds Crystalline Glaze Vase

Found this vase today. The mark was hidden by the price sticker so I did not see it until I got home.

I love the glaze on it with the spots and blue at the top.

The mark has some text and then there is the rest. I rubbed some cornn starch in the mark so it would be more visible. The text looks to be S_N_. The bottom portion looks to have a stylized Y, or it may be another language. I still can't make it out very well. I was hoping someone here might recognize it.

This is French Pierrefonds crystalline glaze vase.

The mark is not totally there. Here is an intact example.
http://www.jasonjacques.com/works/pierrefonds/