Rajon Rondo’s Tattoos Confuse Me

I really like this shot of Rajon Rondo practicing his shooting while the Boston Celtics train in Europe—recapturing the Ubuntu spirit which got them banner #17. That said, I never realized that he has "RR" tattooed on his back. 

Um. Why?

He already wears clothes with his name on the back of them, is he really that concerned that he might forget his name or initials? I don't get it…

Can anyone explain this to me? 

[Boston Celtics]