Below are the official naval and marine ranks, compared side-by-side. Command staff are of course free to use other styles and even other ranks depending on their sim’s plot and era. But these are the defaults for the fleet and for most sims.
Officers
[table id=7 /]
Warrant Officers
[table id=8 /]
Enlisted
[table id=9 /]
Cadets
[table id=10 /]