United States Navy service numbers were created in 1920, one year after the close of the First World War. The creation of Navy service numbers coincided with those of the Marine Corps, as the Marines were under the authority of the Department of the Navy.
Apart from the prefix codes B, and D which were the standard prefix codes for all B and D series service numbers, the Navy used the suffix W which was issued from 1948 until the late 1960s to female enlisted personnel. The "W" suffix was written behind the service number of any officer or enlisted Navy member who was a woman. This practice was discontinued in early 1970, shortly before the discontinuance of service numbers as a whole.
During World War II and into the 1960s, Naval Reservists would receive a classification code that was written after the service member's rate, rank, or service number. These codes would provide additional information about the Naval Reservist and, in this way, were the equivalent of a service number prefix. The Navy used a total of twelve "V-codes" for members of the Volunteer Reserve as well as two "O-codes" for members of the Organized Reserve. In all, these fourteen codes were as follows:
|Naval Reserve Volunteer Code||Meaning|
|V-1||Naval Reserve Officer Training Corps member|
|V-5||Naval Aviation Cadet|
|V-6||General Service & Specialists|
|V-7||Midshipman Officer Candidates|
|V-8||Aviation Pilot Training|
|V-9||WAVES Officer Candidates|
|V-10||WAVES Enlisted Personnel|
|V-11||Officer Candidates "O-Group" (Older candidates)|
|V-12||College Training Program|
|O-1||Organized Reserve (Seagoing)|
|O-2||Organized Reserve (Aviation)|
Significant Navy service numbers include: