Take the horizontal layout of the drawing as an example:
The left side of the inner frame is offset by 25mm from the outer frame, which is used to leave the position of the countersign bar, and the other three directions are offset by 10mm from the outer frame.
The inner frame is drawn with a thick solid line of about 1mm width, and the countersign bar can be put on the right side or at the bottom of the inner frame according to the different formats.
I don't know if this is clear? Throwing in the towel