My point is you are blowing things WAY the hell out of proportion it's a fictional universe an ALTERNATE universe to boot and I changed SS for the fact that you and others complained and actually the Secret Service is just called the Secret Service because it's not exactly hard to say "Secret Service" however "Federal Security Division" is a little cumbersome don't you think?
Also MI-5 you also have MI-6 and they are two seperate branches that are both related to intel so it fits

and actually it's "Her Majesty's Security Service" so it would be HMSS but you don't hear anyone calling it that do you?
Just like Her Majesty's Secret Service
Like I said I think you are just reading too much into it I seriously doubt any reader who has not been forwarned that I am changing SS to SD would read much into it. I mean hell the initials of a Super Dreadnought are SD do you want me to change those too?
And yes I remember the "Fuss" and I changed it because of that fuss I am not going to be giving myself headaches over the fact that you are unhappy with INITIALS THAT DON'T EVEN STAND for the same thing the German SD did
And like I said if you would please translate what SD and SS are short for in German (tell me what their names mean IN ENGLISH) are they even close to Security Division? Because if it is then I will change it.
Federal Security Division is a unique name as far as I am aware while "Imperial Security Force" is used a LOT in Sci-Fi or at least the initials ISF.