2013 California Standards for Accessible Design Pocket Guide

11B-411.2.1.3.4 Position.

The face of individual elements or group of individual elements that are operated by user input shall slope away from the user at 15 to 25 degrees from the vertical plane.  The face of hall call console assemblies and the face of touch screens shall be sloped away from the user at 7 to 25 degrees from the vertical plane. Display screens and touch screens shall be positioned so glare is reduced on the screen.