I read 6th book several times i m sure that this R.A.B. will play imp role in 7th book. R.A.B. was death eater as he called voldemort dark lord.
I think it is Regulus Black. but it maybe R.A.B is two people and the "a" stands for "and". or it may be RABastan.
any guesses frm u guys? what do u think about this topic?
P.S. i am sorry if anyone already started this topic