I own a Ross Mk2 that was purchased by the US. When the rear sight is raised, the sight can be adjusted for windage and elevation, and the peep sight is used. My question is, what is the notch for that is directly above the opening used for the peep sight. The peep sight in the photo is set for 300 yards. Is the notch above the peep now set for 700 yards as indicated by the < on the sight?

I believe that the fixed notch at the top of the sight is for max elevation.

Thanks for looking at this.