An alternate RAB theory.

[Goddlefrood]

No: HPFGUIDX 142743

--- In HPforGrownups at yahoogroups.com, "Justin" <downtownnac at y...> 
wrote:
... no one has mentioned Borgin or 
> Burke (I might be wrong in the spelling) the owners of the Dark 
Magic 
> item shop. Riddle worked for them for a time, and they are both 
> knowledgable about all kinds of dark items. Who's to say they didn't 
> snatch the thing to sell?

Goddlefrood says:

Caractacus Burke does not fit with the initials. Borgin may and has 
been speculated on. One of the editorials on Mugglenet mentions him 
and sets out reasons as to why it could be Borgin.

>From my reading of canon Borgin does not seem the type, but then many 
of us have been wrong before. He is certainly familiar with curses and 
would most likely be familiar with Horcruxes. In fact he would be a 
prime candidate to have taught LV about how to encase a Horcrux in an 
object. If this is then the case it is unlikely that he would say in a 
note to LV that he has discovered the secret. Additionally he is still 
alive and there is no reason to suppose that the author of the R.A.B. 
note did not have a good reason for believening that he / she would be 
dead by the time LV read the note.

Filch could have been many things, but as a squib I do not believe 
that he was at Hogwarts any earlier than during the time of the 
Marauders. It is Mrs. Weasley who reminisces about the previous 
caretaker being there in her time.

Goddlefrood