Yup but as I said sometimes manus will use those old 9 pinners in different wiring configs.
I have been unsuccessfully prowling the intertoobs to see if I could find the symbol but am not having much luck.
I am almost CERTAIN I've seen that symbol before back when I was slaving away in the electronics surplus mines.
So for now I'm just gonna assume it's a custom daughter board meant to hook up to a break out box or other doodad.