All ships of the seagoing services of the United States Government except for the United States Coast Guard fly the national flag as their ensign, although the ships of some agencies also fly an agency flag as a distinctive mark.
Countries like Ukraine, Italy, Russia, South Africa, Australia, New Zealand and Japan use different ensigns.
[3] This flag signifies the home port of the ship owner and that taxes for ship-related income are paid there.
[citation needed] With the creation of independent air forces and the growth in civil aviation in the first half of the 20th century, a range of distinguishing flags and ensigns were adopted.
In heraldry, an ensign is an ornament or sign, such as the crown, coronet, or mitre, borne above the charge or arms.