The small vs. large variety only occurs in the FIRST letter of the prefix.
That said, the BUB prefix is the "small/small" variety. The BFB prefix is the "large/large" variety. Both notes are quite common.
Logged
BWJM, F.O.N.A.
Life Member of CPMS, RCNA, ONA, ANA, IBNS, WCS.
President, IBNS Ontario Chapter.
Treasurer, Waterloo Coin Society.
Show Chair, Cambridge Coin Show.
Fellow of the Ontario Numismatic Association.