While there are many variations in specific countries, the lowest-ranking petty officer is the lowest-level supervisory rank that is concerned with the training and supervision of individual sailors, which complements the officer track that deals with the training and supervision of units. Petty officers have a rating that describes their specialty, and a rank within the specialty.
Depending on the service, the highest level petty officer grade is commonly some variant of "chief petty officer". Warrant officer titles may be, as in the Royal Navy, the highest rank of petty officer, or, as in the U.S. Navy, a technical specialist that is a specialized, not necessarily supervisory promotion track for senior petty officers.
There are various traditional titles for the most senior petty officers of a command, which often no longer contain the rating part of the title. For example, the most senior petty officer of a U.S. Navy unit is the Command Master Chief, except that on submarines, that individual is called the Chief of the Boat. Several navies refer to the senior chief as the Boatswain (pronounced "bosun"), even though that individual might be an electronics specialist rather than being qualified in the Boatswain rating. There are many, many variations and traditions; navies tend to have more specialized language than the other military services of the same country.
- Raymond Oliver. Why is the Colonel called "kernal"? The origin of the ranks and rank insignia now used by the United States armed forces, McClellan Aviation Museum. Retrieved on 2011-04-22. mirror