The first digit of the two-digit prefixes is the denominational letter.
These letters are as follows:
BABN:
$1: A, G, L, M, N, O
$2; B, R, U
$100: J
CBN:
$1: F, I, P
$5: C, S, X
$10: D, T, V
$20: E, W, Y
$50: H
Unused:
K: Reserved for $1,000
Q: Never used
Z: Not needed
The above information was determined based on orientation of asterisks and ranges of plate numbers. The $2 through $100 notes were only printed by one company per denomination, but the $1 notes were printed by both companies. BABN printed the vast majority of $1 notes (A, G, L, M, N, O), but CBN had a few in there too (F, I, P).
This information is not yet in the Charlton guide (AFAIK - maybe I missed it, but I checked), so I'll try to get it included in the GPM22.
[edit]Reorganized layout of data --BWJM[/edit]
« Last Edit: February 17, 2009, 12:26:46 pm by BWJM »
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.