I’ll be honest with you, when I first started the community I created a rank structure that I liked. I have read sci-fi, watched sci-fi and read/ watched military fiction and historical stuff too. I basically drew on a whole load of things and came up with the now established rank structure.
The reason why it is ‘acting’ is just because we have that period of time until you complete a ‘real’ mission. Earlier in our history, cadets wouldn’t take part in missions, just simulations. Our current numbers don’t allow that so they come along on missions. It basically showed you had passed and qualified as an officer, but had not seen active service on a mission.