Could somebody inform me what the prefix letters "BC" prior to the numbers mean on a Canadian Passport. is it the Province British Columbia?.

Without a meaningful title your thread might not draw much attention?

 

I have no expertise, just googled here and there and doubt that the letters refer to a certain province as I didn't not see any hint.

 

From Google appears it is just adding quantity to the number of passports that can be issued with the limited set of numbers used.  Just like a Thai vehicle plate where letters are used to allow more.

I have had several Canadian passports over the years, including one obtained in Vancouver. The letters on that one were not "BC". To my knowledge, the letters used are random.