Multilevel precedence and preemption (MLPP): In military
communications, a
priority scheme (a) for assigning one of several
precedence[?] levels to specific calls or messages so that the
system handles them in a predetermined order and
time frame, (b) for gaining
controlled access[?] to
network resources in which calls and messages can be preempted only by higher priority calls and messages, (c) that is recognized only within a predefined
domain, and (d) in which the precedence level of a
call outside the predefined domain is usually not recognized.
Source: from Federal Standard 1037C