autoresizingMask for fixed margin sizes

Question

In a view containing several subviews, one of the subviews should remain a fixed, non-zero distance from the top and bottom of the superview. In these images, this view is shown in gray:

According to the documentation, this view should have a mask of UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth. However, this causes the view to expand its height to take over the entire superview. How can the view be contained to fixed, but non-zero margins? Thanks.