Duality

Acronyms tend to be quite informal, so the layman is usually the target audience. As long as you don't inconsistently leave some joining words out of the acronym while leaving others in (i.e., TARDS) it's not too ill-formed. There's no official ruling on a lot of things that are blights upon our already-blighted language, which is basically the only reason we have journalistic standards (APA might say something on the topic).

On a slightly related note, 'Time and Relative Dimension in Space' is hands down the worst name for anything I've heard in my life. For a start, it doesn't say anything about what the thing actually is (since the TARDIS is not, itself, time or space or any 'relative dimension', unless there's some really weird Doctor Who lore lurking somewhere I haven't heard) and furthermore time isn't in space and there aren't any 'relative dimensions' in space either. It fails to describe its subject, it implies bizarre falsehoods, and as a result it holds no meaning whatsoever except as an arbitrary sequence of phonemes associated with an object (fictional, at that). It's like a philosophical thought experiment designed to stretch the boundaries of what can realistically be called meaningful. 

Technically, The TARDIS is mostly the pocket dimension produced by the alien machine. I do believe it is named after its result, not its specific mechanics.

 Like a can opener.

Ya don’t call it “Circular Blade at top of Gear Tower Placement.” 
 Besides, it’s technically a whole seperate alien culture with its own naming conventions.

 Way I read it, there is an awful lot of technical specifics left off. It is more like: Time (manipulation) and (its relation to the) Relative Dimension (as produced together in conjuction to a seperate zone of what is outside of it) in (its exterior) Space 

 Basically, a Time Bubble. Housed by supporting mechanics. Breaking causal relation to time & space outside of it can't be done by merely one or several devices. You know how many times that thing has broken down? ...to produce drama for the episode? Why, one time it even became sentient! And confessed a crush on the Doctor! But I do suppose having a being live inside you would tend to promote complicated feelings.

I know that's usually the case with tapeworms.

 But now I've forgotten what we were talking about!

 Edit: (Yes, I hadn't even left the page.)

 Oh yes, I was having an internal mental implosion over your intonation of informality.

 The whole POINT of acronym-ing is to convey technical knowledge! As in, naming something in regards to the specifics of its use, to those of whom would also be in privvy to what aspects stand for, to the point of not requiring the whole of the name to identify the subject referred. Which is why A.S.P.C.A works. You know what it stands for, because you know what to go to that organization for.

 You can't just tell someone to hand you the M.F.P and expect them to know it means My Fluffy Pillow! We have RULES and ORDER so that we may FUNCTION as a WHOLE, FUNCTIONING SOCIETY! Anything less than perfection is ANARCHY!! ANARCHY!!!

 Oh, pardon me. Think my OC needs a calming bath.

 I'm not your Original Character.

Nope, that stands for Obsessive Compulsive.

 Oh, I can go for that.  .... ....WHY IS MY HAIR NEVER SYMETRICAL?!!? SYM-METRY! SYM-METRY!!