You sure it's not "P-1"?
Our regular code book is
CEC Part I - Safety Standards for Electrical Installations (C22.1)
"This Code covers all electrical work and electrical equipment operating or intended to operate at all voltages in electrical installations for buildings, structures, and premises, including factory-built relocatable and non-relocatable structures, and self-propelled marine vessels stationary for periods exceeding five months and connected to a shore supply of electricity continuously or from time to time, with the following exceptions:" (exceptions are planes, trains, boats, and utilities)
On the other hand, they're on the other side of the Great White North, so it could be that I've never heard of "B-1"