There are a few organisations named "FRS" but mostly I doubt that anyone of them would take Sphiel.
Then I looked for blogs with generic meanings for the S that would do things like this.
Squad, Society, etc.
I found this.
Wierd of it to start so close to the time I searched...
Anyways, im going to keep looking on this blog.
This also gives some light on another blog that The Story Teller mentioned in chapter 1.