The use of bort numbers to identify Soviet aircraft within specific squadrons dates to
World War II, however the modern system of applying bort numbers was not formalized until 1975. The modern bort number format consists of a two-digit number which is most commonly red, but may also be blue or yellow. On all aircraft except bombers, the bort number is shown on the side of the fuselage, typically near the cockpit. On bombers the bort number is shown on the
vertical stabilizer and nose wheel door. Bort numbers serve the same purpose as the US military tail code system: to provide a means to identify a specific aircraft in a squadron without the use of the aircraft's
serial number. Unlike the tail code system, bort numbers are not unique to a given aircraft, often change over time, and are not attributable to a certain base or squadron without additional context. Bort numbers are assigned by the local airbase commander, with a few common rules: • All aircraft at a given base must have the same bort number color. == See also ==