I'm not certain KM, but check this out:
[Rank 12]
ID=LT
Level=12
TreeType= USNavy
NameDisplayable=Lieutenant
Image=5
3DClothingIDLink= ClothingO3
XPRequirement= 8150
LevelUp= Base
MaxQualifications= 1
MaxSpecialAbilities= 1
AvailableQualifications= NULL
AvailableSpecialAbilities= Ability-Master-Engineer, Ability-Sharpshooter, Ability-Torpedo-Specialist, Ability-Torpedo-Expert, Ability-Medic, Ability-Engines-Expert, Ability-Propulsion-Specialist, Ability-Expert-Sonarman, Ability-Expert-Radarman, Ability-Watchman, Ability-Radioman, Ability-Theoretician, Ability-Active-Stalker, Ability-Active-Overcharge, Ability-Active-Riposte, Ability-Active-Bombarde, Ability-Active-Quick-Repair, Ability-Active-Quick-Escape, Ability-Active-Perfect-Pitch, Ability-Active-Medic, Ability-Active-Sensors-Alert
GetSpecialAbilityChance= 1
EfficiencyMod= 1.0
DescriptionWhenPlayerHasTheRank=The player has the
DescriptionWhenPlayerDoesntHaveTheRank=Description of the
[Rank 13]
ID=LTCDR
Level=13
TreeType= USNavy
NameDisplayable=Lieutenant Commander
Image=5
3DClothingIDLink= Clothing04
XPRequirement= 20000
LevelUp= Restricted
MaxQualifications= 1
MaxSpecialAbilities= 1
AvailableQualifications= NULL
AvailableSpecialAbilities= NULL
GetSpecialAbilityChance= 0
EfficiencyMod= 1.0
DescriptionWhenPlayerHasTheRank=The player has the Rank <b>LTCDR</b>
DescriptionWhenPlayerDoesntHaveTheRank=Description of the Rank <b>LTCDR</b>
Notice that the Lieutenant is missing some of the text... I doubt if that has anything to do with it, but the "XPRequirement= 20000" might... ?? From the looks of it, the Lieutenant rank is not meant as a player rank, since it has "LevelUp= Base". Maybe if you change that to "Restricted" and change the info text, like the other player ranks? dunno though. You would probably have to add a <LT> description to one of the text files also, for those description lines, but I cannot find a file for that. Let us know how it goes though, if you can get it to cooperate with you.