Sub-lieutenant

He wears a band in the colour of his corps (e.g. gold for infantry, silver for armoured cavalry, etc.).

In Mexico, the sub-lieutenant is the most junior officer in the rank scale, and wears a single gold bar.

[6] A midshipman who became a master's mate got an increase in pay from £1 13s 6d to £3 16s per month, but initially reduced his chances at a commission.

The situation caused some confusion during the last part of the 18th century, when two parallel roles—master's mates trying to become masters, and former midshipmen working toward a commission—held the same title and responsibilities aboard ship.

[7] In the modern Royal Navy, all officer cadets now commission as midshipmen, regardless of whether they are a graduate or a school leaver.

In the Royal Canadian Navy, all undergoing basic officer training join as naval cadets, but upon graduation, those who joined with a bachelor's degree receive an immediate promotion to acting sub-lieutenant, while those who do not retain their rank as naval cadet until such time as they finish more career-related training.

The equivalent air force lieutenant rank has the narrow stripe above the medium stripe since these elements do not need to maintain spacing on top due to the lack of an executive curl; the Royal Canadian Navy followed this pattern before the addition of the curl in 2010.

In 1955, the Royal Navy created the rank of acting sub-lieutenant, although it had existed intermittently in the world wars.

Unlike their substantive counterparts, acting sub-lieutenants are subordinate officers, as they hold their ranks by order and not by commission.