Message precedence is an indicator attached to a message indicating its level of urgency, and used in the exchange of radiograms in radiotelegraph and radiotelephony procedures.
Email header fields can also provide a precedence flag.
For example, in the period around 1909, California required that "messages must, if practicable, be transmitted immediately on and in order of receipt; if not practicable, then in the following order:"[1] Later in the development of telegraphy and radiotelegraphy, message precedence was nominally set by the International Telecommunication Union (ITU).
Various ITU Regulations provide for the following priorities:[2][3] The U.S. Code of Federal Regulations, Title 47, has included the following priorities:[4] The current U.S.
Title 47 specifies these precedence designators for radiograms:[5] The Combined Communications Electronics Board (CCEB), a five-nation joint military communications-electronics organization (consisting of Australia, Canada, New Zealand, the United Kingdom, and the United States), uses the following message precedence designators, in descending order of importance: The American Amateur radio community uses EMERGENCY, PRIORITY, WELFARE and ROUTINE precedence levels for ARRL Radiograms sent through National Traffic System nets.