Mobile Data Terminals (MDTs) give police officers a second means of communication with the dispatch center and with each other. A significant number of messages do not require voice communications, such as routine status changes and database inquiries. Important MDT capabilities include: The ability to receive calls for service displayed on a screen, thus reducing voice-radio congestion. Direct access to computerized databases to obtain want/warrant, stolen vehicle, DMV and other information without having to go thru the RadioTelephone Operator. Digital messaging from car to car, to the station or to Communications Division, and One-touch "Officer needs Help," officer needs "assistance," and request "back-up" buttons, which signal Communications the unit's identification and last known location.