If you take a moment to look at your computer keyboard or even the keypad on your home phone or your cell phone, you should see that more often than not, certain keys are marked with either a dot or some sort of cut edge. For the phone's keypad, there is often a raised dot on the #5 key and on several computer keyboards, there are cut edges placed on certain keys such as the f and j keys. Some phone keypads may even have a raised dot on the #0 key as well and I do believe that some remotes are similarly configured; either with a dot, a raised edge, or keys of different shapes.
In the normal scheme of things, there are many blind persons who depend on these very subtle indicators to help them quickly locate keys on their keypads. Keys with dots, cut or raised edges, and keys with different shapes often save me from pressing the wrong key and I am grateful for them. Now, if only we could find a way to standardize all keypads in this way and if it is already a standard then I do apologize. Blind persons need keypads to help them communicate with their devices; they are unable to use devices with touch screens. What would be ideal is if manufacturers were to come up with accessible ways for blind persons to be able to communicate with touch screens.