Air Canada vs Jazz, what's the difference?

[Jonathank]

When Jazz aviation started in northern Ontario, the 4 digit flight numbers started with 7***, or Jazz 7820 etc.  A few years ago, those flight numbers changed to start with 8***. For example, Kingston to Toronto is advertised to the public as AC8001, but the flight plan is JZA001 or Jazz 1. Why does the 8 drop out, and reduce the ATC version as 3 digits?

Also, my sincerest appologies if this question belongs in another forum.
 

[KB4TEZ]

here's more information than you'd ever want to know about it

https://www.flyertalk.com/forum/air-canada-aeroplan/812641-ac-flight-numbers-numbering-convention.html