WELL STOP IT.
They are the Elements of Harmony, not the Mane 6. I know people understand that, but imagine having a pony read it...
Who the hell are the "Mane 6"?
So basically: never ever say that word in the description of your story, or in your story at all. (unless it's HiE)

981085

I prefer "the element bearers." the Elements are the shineys, the bearers carry them.

For me, it's not the fact that they aren't called by a proper title, it's the fact that they are being called the Mane Six instead of the Main Six. After all, who in Equestria would think along the lines as to make a out-of-nowhere-for-their-universe pun?