This is a test page for a CSS Sprite technique that works with high contrast mode. Below are two disclose icons (click to show details). The first uses normal background positioning and the second uses JavaScript to convert the CSS background into a positioned image. When you go into high contrast mode you will see the first disclose icon disappear (along with the annoying background image under this paragraph). The second icon works even in high contrast mode.
FYI: Not in high contrast mode.