Clear message

In telecommunication, the term clear message has the following meanings:

1. A message that (a) is sent in the forward direction and the backward direction, (b) contains a circuit-released signal or circuit-released acknowledgment signal, and (c) usually contains an indication of whether the message is in the forward or the backward direction.

2. A message in plain language, i.e., not enciphered.

Source: from Federal Standard 1037C