The combination of the Bravo and Zulu nautical signal flags, i.e., Bravo Zulu, also referred to as "BZ," is a naval signal, typically conveyed by flaghoist or voice radio, meaning "Well Done" with regard to actions, operations or performance. In addition to the British Royal Navy, it has also been used as part of vernacular slang within NATO and other Allied naval forces. It can be combined with the "negative" signal, spoken or written as NEGAT, to say "NEGAT Bravo Zulu" to convey "not well done" for a given action. "BZ" is widely used as shorthand vernacular amongst members of the sea services. In the Royal Navy, when the sovereign wishes to reward the crew of a British warship with the order to "splice the mainbrace," it is ordinarily followed simply with Bravo Zulu.
History
The term Bravo Zulu originates from the Royal Navy signal flag system whereby each letter flag had a number of additional meanings in order to shorten messages. The Bravo flag had, among other meanings, the word "well" assigned to it and the Zulu flag, again, amongst other meanings, had the word "done" assigned to it. The expression "Bravo Zulu" meaning "Well done" therefore predates the formation of the US Navy. The references below should only be considered appropriate for countries with a national identity of less than 300 years. According to the "Navy Data" reference website operated by the U.S. Navy: "The term BRAVO ZULU originates from the Allied Tactical Publication 1, an Allied military maritime tactical signals publication, which in the aggregate is For Official Use Only, and can also be found in Multinational Maritime Tactical Publication 2. Signals are sent as letters and/or numbers, which have meanings by themselves sometimes or in certain combinations. A single table in ATP 1 is called 'governing groups,' that is, the entire signal that follows the governing group is to be performed according to the 'governor.' The letter 'B' indicates this table, and the second letter gives more specific information. For example, 'BA' might mean 'You have permission to...'. 'BZ' happens to be the last item of the governing groups table and it means 'well done'." "Bravo Zulu" is also defined by the Allied Naval Signal Book, an international naval signal code adopted after the North Atlantic Treaty Organization was created during 1949. Until then, each navy in NATO had used its own separate signal code and operational manuals. World War II experience had shown that it was difficult or impossible for ships of different navies to operate together unless they could communicate readily and the implementation of ACP 175 was designed to remedy this.
In addition to flaghoist and military voice radio, use of the term BRAVO ZULU has also been extended in contemporary times to include written correspondence, message traffic and email traffic from the Canadian Coast Guard, U.S. Navy, U.S. Marine Corps, U.S. Coast Guard, National Oceanographic and Atmospheric Administration, DE&S Typhoon Delivery Team and US Public Health Servicecommissioned officers in command or senior supervisory positions to congratulate or otherwise compliment colleagues, contemporaries, or juniors, the latter to include their subordinate crews or commands, for outstanding performance.