Similar to the standard phone feature except that many cellular phones allow storage of not only a phone number but the person's or company's name as well. This is called an alphanumeric name tag. Tags can be more than 20 characters long and allow you to access voice mail automatically. To prevent dialing mistakes, some phones require you to hold the key that activates speed dial longer. All cellular phones include a screen, usually LCD, to display operational messages such as power, status, phone number dialed or received, and signal strength.
Many phones display time elapsed of the call.
The type and angle of the display can be important because you read the display fleetingly while you're speaking. Before buying, see how well you can read the display in the dark and in a brightly lit car. Most car-based phones are speakerphones, which allow you to keep your hands on the wheel while speaking. Making a call can be dangerous, particularly when in traffic. The function key accesses most of the carrier-supplied services.