I just noticed something in the new Charlton guide - a paragraph on pg 311, dealing with the Birds of Canada series, which I have copied below.
For several years the Bank of Canada has been assessing methods of making denominations of banknotes distinguishable by the blind and the visually impaired. To assist the blind, the notes of this series were printed so that the denomination can be read by a small handheld electronic device ....
Under the Journey series (pg 336) the Charlton guide also states that an improved handheld denomination reader is being developed.
I hadn't heard of such a thing before, though I certainly knew about the braille aspects and the high-contrast numbers. Presumably though, these handheld devices must read more than just braille (since blind people don't generally need a machine to read braille).
Does anyone know more about these machines? What do they actually read from the bills?