Lieutenant

In most militaries, a Lieutenant is a platoon or lance commander. In naval or administrative settings, they command departments or sections.

SLDF

In the SLDF many Lieutenants were "mustangs", non-commissioned officers who were so capable that they went to Officer's Candidate School. Unlike many other militaries, the SLDF did not immediately commission graduates of military academies as Lieutenants. These recent graduates were instead made Sergeants until they distinguished themselves on the battlefield.

SLDF Lieutenants wore a simple olive green bar as their insignia.

Lyran Commonwealth and Lyran Alliance

In the LCAF, a Leutnant is the rank given to recent academy graduates while they demonstrate their technical and leadership skills. Uniquely, the Leutant has not yet won a commission, and is technically not an officer, similar to the AFFS rank of Subaltern. A Leutnant is frequently referred to by their job title, for example, MechWarrior, Gunner, Pilot, etc.

Once a Leutnant demonstrates their leadership abilities, they are promoted to the rank of First Leutnant, and given permanent command of a lance or platoon.

Draconis Combine Mustered Soldiery

In the DCMS, a lance or platoon leader holds the rank of chu-i. These officers wear a royal blue katakana number 3 as their rank insignia. In the Draconis Combine Admirality these officers are called Sho-i (Ensign).

DCMS Officer Ranks by branch of service

Rank	MechWarrior	AeroSpace Fighter	Infantry	Armor	Artillery	Naval Crew	Technical Service
Chu-i (Lieutenant) Sho-i (Ensign)

Armed Forces of the Federated Suns

In the AFFS a Leftenant is a lance or platoon leader. This rank is equivalent to Lieutenant. They wear an epaulette in their branch color as their rank symbol.

AFFS Leftenant insignia by branch of service

Rank	MechWarrior	AeroSpace Fighter	Infantry	Armor	Naval Crew	Technical Service	Administrative	Medical	Legal	Logistics/ Transportation
Leftenant

Capellan Confederation

The "modern" CCAF uses the rank of Sao-wei for officers who lead platoons and lances. In the CCAF Navy, this rank, like all officer ranks, adds the Kong- prefix. Kong-sao-weis lead sections or departments on a CCAF WarShip. Their insignia is a simple brass bar.

CCAF Military Ranks

CCAF Rank	Insignia
Sao-wei Kong-sao-wei (Lieutenant)

Free Worlds League

Traditionally, the FWLM divides Lieutenants into two ranks: Lieutenant, Junior Grade (Lieutenant JG) and Lieutenant, Senior Grade (Lieutenant SG). In any case Lieutenants serve as lance/platoon leaders or staff officers.

The Clans

In the Clans, Lieutenant doesn't appear as a rank. Instead Stars (a Clan lance) are commanded by Star Commanders.

ComStar/Word of Blake

Neither Comstar nor the Word of Blake use Lieutenant in their ranking system. Instead six-element Level II formations (Demi-Companies) are commanded by Adepts.