As an informal researcher with access to data in the SNDB. it is part of my mandate to provide information about the notes that our contributors have entered. Most prefixes contain 10 million notes, with some obvious exceptions like changeover prefixes. When there is evidence that a prefix is not printed completely, many collectors and other researchers would likely want to know about it.
Prefix ERG is a Journey series $20 prefix printed in 2008. I have prepared a short summary of the serial number data as follows:
ERG 0000000-1799999 : 227 notes in SNDB (33% of all notes entered)
ERG 1800000-2879999 : 0 notes
ERG 2880000-2913749 : 5 notes in SNDB (<1% of all notes entered)
ERG 2913750-6629999 : 0 notes
ERG 6630000-9999999 : 455 notes in SNDB (66% of all notes entered)
So, as you can see, there are only 5 notes recorded over 1800000 and below 6630000, and those 5 notes form a cluster. I would consider the data for prefix ERG to be mature at this point in time, meaning that I don't believe that notes will be found in the ranges where no notes have been found to date.
The 5 notes that form the cluster have the following serial numbers and position numbers:
ERG 2887895 10/14
ERG 2889245 17/23
ERG 2895443 35/49
ERG 2895542 35/49
ERG 2911112 11/48
Not coincidently, I found ERG 2889245 17/23 today.
I have determined that these 5 notes were not printed with the usual skip interval of 8,000 that is common for nearly all $20 notes printed by the Canadian Bank Note Company. The skip interval appears to be 750, and if all 45 positions of the sheet layout were used, the interval ERG 2880000-2913749 represents a range of only 33,750 notes.
Had prefix ERG been printed normally, notes in the range ERG 1800000-2879999 would represent 3 normal reams printed with a skip interval of 8,000. So at ERG 2880000, another ream would be expected to start and run all the way to ERG 3239999, representing a ream of 360,000 notes. But of course, we don't see that in the data. Normal production of notes does not start again until ERG 6630000, and that's not a "normal" starting point for any ream.
So, in conclusion, prefix ERG is not a complete prefix, meaning it does not have 10 million notes printed with it. It has only just over 5.2 million notes. This makes ERG a short prefix, but certainly not a rare one (except in the range 1800000-6629999). As expected, there is no explanation for why we are seeing the odd distribution of serial numbers at the start and the end of the prefix. Had there been absolutely no notes found in the range ERG 1800000-6629999, then there is the possibility that these notes are sitting in some vault somewhere waiting to be released if they have not been destroyed leading up to the release of the new polymer series. But because notes in the range ERG 2880000-2913749 have been found, and because we know that they were printed differently (i.e., with a skip interval of only 750), then it becomes extremely unlikely, in the humble opinion of this researcher, that notes in the ranges ERG 1800000-2879999 and ERG 2913750-6629999 ever existed or, had they existed, were ever slated for release.
I have ERG 2889245 in my hand, and it is a moderately circulated note that would grade VF. It appears to be an ordinary note with no unusual features. I am going to hold on to it for now, and maybe in time, we will find out if the Bank of Canada released any test notes in prefix ERG.
Your comments and questions are welcome.