Standard for a Round Tactile Indicator (CTA-2041-A)

If you’re visually impaired, or just trying to use a remote control in the dark, it can be hard to know what key you’re pressing. CTA-2041-A addresses this problem by defining a standard numeric keyboard layout that matches the one used on telephones, and also by defining a raised bump, or “nib,” that is placed on the “five” key. Without seeing the keyboard it’s easy to locate the key that represents five by feeling for the nib. From there it’s known that the key above it is two, the key to the left of it is four, etc.