I you look at the AO series from BABN You would come up with approx 53,760,00 notes which is an odd number. I'm sure the BoC"s order would have been a number that was even like 50,000,000. That would leave 94,000 sheets or 3,760,000 notes missing from what was delivered within the 6 prefixes.
If you deduct the 300,000 known AOB inserts which have been found in ranges from 2.30 - 2.60 you still have 3,460,000 notes in question. These 3,460,000 or $17,300.000.00 would represent more than all the counterfeited money found in 2002. AO was only one order of one denomination so you can see there are hundreds of millions of dollars of notes notes each year not accounted for under the BoC's stated system.
The point I am trying to get to here is that the BoC HAS to know what inserts are been used. If they don't, then how could they ever figure out if any of the possible 3,460,000 fives coming back for destruction were supposed to be in circulation in the first place. If you don't know exactly what you put into the system how could you ever tally whats coming back.
Sounds like an accountants worst nightmare to me.