Sometimes shortened to proword, a procedure word is one of a set of words used over radio communication in military and civilian endeavors. Often used when one or both parties are traveling, such as in ships or planes, procedure words allow clear, concise communication with little chance of misunderstanding. Although they are often used in general communication, they are frequently employed in emergency situations.
There may be some minor variations among which procedure words are used for a given organization, but overall these words are internationally recognized and have the same meanings across countries and organizations. Procedure words are generally used for several tasks, such as to ask or confirm the clarity of a signal. They also indicate a message is incoming or completed, has been received, or needs to be repeated. Additionally, they quickly inform of an emergency situation.
Signal checks are often used before any actual message is transmitted. Used to determine the clarity and strength of a connection, signal checks are usually instigating by one party using the procedure word "radio check" or "how do you read." Signal strength and the clarity of the received transmission are determined on five point scales with each point corresponding to a different word.
For example, a five in strength is "loud" and a five in clarity is "clear," whereas a two in strength is "fading" and in clarity is "intermittent." The responder can either use the procedure word "loud and clear" or "five by five" to indicate a strong, clear connection or "fading and intermittent" or "two by two" to indicate a poor connection. Alternately, if the signal is "loud and clear" the procedure word "roger" meaning "received message" may also be used.
Many procedure words indicate nearly the same thing, but have minor differences in meaning. For example, like "roger," "wilco" is used to indicate a message has be received but also indicates any instructions in that message will be carried out. Similarly, the words "over" and "out" both indicate a transmission has ended, but unlike "out," "over" implies a response is required. Other prowords are designed simply for enhanced clarity in a response. For example, any yes or no answer is given as "affirmative" or "negative."
Although procedure words assist in clear and quick communication in any radio messaging situation, they are particularly important during an emergency. Possibly the most well known emergency procedure word is "mayday." This word generally starts a distress call, usually on a ship or plane, and is repeated several times at the beginning and again at ending of the message.