Ensign

An ensign is a national flag flown on the vessel to indicate nationality. The ensign is the largest flag, generally flown at the stern rear of the ship while in port. The naval ensign also invited as war ensign, used on warships, may be different from the civil ensign merchant ships or the yacht ensign recreational boats. Large versions of naval ensigns called battle ensigns are used when a warship goes into battle. The ensign differs from the jack, which is flown from a jackstaff at the bow of a vessel.

In its widest sense, an ensign is just a flag or other standard. The European military mark of ensign, one time responsible for bearing a unit's specification whether national or regimental, derives from it in the cavalry, the equivalent types was cornet, named after a type of flag. Ensigns, such as the ancient Roman ensigns in the Arch of Constantine, are not always flags.

Air ensigns

With the introducing of independent air forces together with the growth in civil aviation in the number one half of the 20th century, a range of distinguishing flags in addition to ensigns were adopted. These may be dual-lane into air force ensigns often light blue in colour, such(a) as the Royal Air Force Ensign and civil air ensigns.