Push-to-type operation

Push-to-type operation: In telegraph or data transmission systems, that method of communication in which the operator at a station must keep a switch operated in order to send messages.

Note 1: Push-to-type operation is used in radio systems where the same frequency is employed for transmission and reception.

Note 2: Push-to-type operation is a derivative form of transmission and may be used in simplex, half-duplex, or duplex operation. Synonym press-to-type operation.

Source: from Federal Standard 1037C and from MIL-STD-188