when the emergency button is pressed. The radio will silently send the emergency message, with the four-digit unit ID embedded, three times. In hand-held radios, this increases the probability of at least one packet getting through. In a computer-aided dispatch (CAD) environment, the button press may pop a dialog box or activate some other attention-getting device. For example, on a screen showing status summary of all units, the unit with an activated emergency button may change colors or flash. Status buttons Some MDC-equipped radios have buttons which allow pre-defined status messages to be sent to the base station decoder. The status messages decode as generic messages, (for example: status 1 or status 8). The user defines . Typically, key caps on the status button for status 8 may be marked with the user-defined definition of the status such as available. The base station may respond to a button press with a voice acknowledgment, for example, "Downtown 6, available." In a CAD environment, the message status 8 may be translated by the CAD system to a meaning such as available. Status 1 might mean starting a meal break. Key caps on the radio's status buttons may be engraved with their user-defined status. The unit's status changes at the moment the button press is received. This helps take a load off the dispatcher because the status change is logged automatically. This happens even though the dispatcher may be talking on the telephone. In systems where the dispatcher is often overloaded, the use of status buttons may slightly reduce the work load and may reduce voice message traffic on a channel. If the acknowledgment packets are enabled, every status button press gets a handshake packet in response from the base station encoder-decoder. The radio where a status button was pressed will normally beep to confirm the decoder's ack for a status button press. Selective inhibit In the event a radio is stolen, or a user's permission to access the radio system is revoked, a data packet can be sent to the radio's ID to disable the radio. This prevents the radio from transmitting or receiving until either an un-inhibit packet is sent to the radio or in some cases re-programmed using the appropriate service software. Some literature refers to this feature as 'stunning' and 'un-stunning' the radio, or a 'radiokill'. Radio check A request can be sent to the radio to determine if