What is this part of the window construction for?
Actually we don't have VSG in the windows (just the RC2N fittings) but this looks like double panes inside and out? It can't be, can it?
Do you have floor to ceiling windows with a bottom fixed section?
Yup, you're right, we have two places. Then that will be a screen for it. I didn't even think about that.
There should be all kinds of text printed in the frame, see if you can make anything out.