I don't have any tatts. (at this point) Personally, I would NEVER get someone's mark permanently on my skin. There is just too many things that can happen that would make that tatt, which was once special, turn into something painful. I think, and hypothetical only, if i were to get a mark of some sort, for someone other than myself, that it would have to be a design and not initials.
With tatts in general, i'm not a fan of them however. I want just one, (though even in my own head, i waffle on this, hence not having it yet) and it'll be in a place where it won't stretch.