Message

Enables the Message feature for the current Conventional System. The Message feature allows the radio-user to select and transmit a specific message from the CPS-defined Message Alias List Window. The Message feature is radio-user activated with a Message button-press, a Direct Message button-press, or a Message menu-selection.

When the radio is model / option capable,

And

((when the System Type field is set to "DVRS" or "MDC"),

Or

(when the System Type field is set to "ASTRO", and

when the Remote Site Interface System field is disabled)).