Well, the first part of this message seems clear.  We
start with one B, then two Bs, then three, four, five
and finally six Bs separated by a pair of Gs, until the
first H appears.  I would guess that this signifies a
base 7 number system.  B is probably 
the unit (or 1) symbol, and G a blank (or space, or _)
symbol.  H, I might guess, is either another number symbol
(like 2) or even more likely the zero symbol (numeric place
holder as in our number 10), or else the H is a major section
separator, like a semi-colon (;).  Of course this last part
is just a guess, but I've started the discussion at least.
            David

Forward

Index