RAB in my opinion in the potter books we know that many people name their kids with a middle name of a relative.

Harry "James" Potter.
Thomas "Marvollo" Riddle.

and I think Ginny has one too...

But anyway i think i remember seeing in one of the books that Sirius had an uncle Albert or Archie or something like that.

SO it leads me too think that Regulus Albert Black ... may be it we know JK does make things obvious some times or maybe it is a red herring.

PS i re did this post as the old one got cluttered...

Let me know what you think ...

Its prob someone unexpected you know JK

Yeah that's what I'm thinking too except he's Sirious's brother isn't he and it makes sense because it says "I'll probably be dead when you read this" And he is dead!

I'm 99.9% sure that it's Regulus Aloysius Black

I've read the book.


[spoiler]It is Regulus Arcturus Black[/spoiler]