How come she sometimes used quotes and sometimes paranthesis?
 

Most of Ayumi's CD put the name of the remix in brackets, like on singles, it's usually, like Beautiful Fighters "Original mix". The majority of her CDs uses this system.

But then, sometimes she just has to use paranthesis to muck this up, like with the Mirrorcle World-single, it's instead (among others) Mirrorcle World (Original mix).

Why? It's just confusing and inconsistent and forces me to check every single single's/album's back cover before labeling the songs.

How do you guys handle it? Do you just use quote marks for all songs, paranthesis for all songs or whatever you feel like at the moment?

I don't tag anything "original mix". Honestly I'm pretty sure this isn't Ayu's doing. It's probably just to guys making the CDs to differentiate it from remixes. It may not make sense originally but I've seen so many stuff mistagged, usually remixes being tagged just as the base name and people assuming it's the original track. Also, there are some slight differences sometimes in sound quality between presses and even between albums. Such as bass line volumes being changed etc. Minor changes that don't warrant a "version" or "remix" extension.

probably to ayu, it doesnt matter. lol

^ agree.. lol