I had forgotten about the rank epaulette images. I don't think the Lieutenant rank has those... hmmm...
This text editing is all in Ranks.upc, btw. It looks like though, that the <LTCDR> text just tells the game to make red, bolded text, so substituting <LT> should work fine there. As mentioned above, I would attempt to change the
XPRequirement= 8150
LevelUp= Base
to something like
XPRequirement= 15000
LevelUp= Restricted
which should then make it a player rank. If the game chokes on that, then delete the full admiral "[Rank 18]" listing, and renumber the others below. I don't see any obvious reason that wouldn't work... though it is SH4...
You'll probably also have to make "AvailableSpecialAbilities= NULL", and should probably set "GetSpecialAbilityChance= 0" to match the other player ranks, unless the mod you are in has those for a player rank. Then just add that "Rank <b>LT</b>" text to the end of the last two lines. Surely it will work without having to delete anything...