Ensign

An ensign is a flag that shows a ship's nationality, usually flown at the stern. Some countries use their national flag as an ensign, while others have separate civil, state or naval ensigns. The word can also mean a military unit's flag.

Ensigns sometimes differ from the flag flown on land. Switzerland's national flag is square, but Swiss ships fly a rectangular 2:3 version. See which countries have square flags. Many British ensigns put the Union Jack in the canton on a red, white or blue field.

If you are designing for a fictional navy or a club, an ensign is a good place to reuse your main flag in the canton. The fictional country flag guide covers related flags, and the flag maker has a canton layout to start from. A narrow, tapering ship's flag is a pennant.