Re: wrong
Er, I think the OP was being a little tongue-in-cheek. The band's name was ABBA, the backwards "B" is just a stylised part of their most famous logo.
I mean, a couple of their older releases used the one seen here, but I don't think anyone (#) counts the uber-1970s "highlight sparkles" are part of the name either. :-)
(#) Except possibly weirdo editors on Wikipedia who add pointless "stylised as" bits to articles...