New language law is in effect

Quebec’s new language law came into effect Thursday – as the CBC says here:

The provisions require employees of most front-facing government agencies to serve clients in French unless those clients have acquired English-language rights or are new immigrants who arrived to the province within the last six months. The acquired rights include that an English speaker be allowed to be educated in English because of their family’s anglophone history.

Does anyone know what the mechanism is for demonstrating one’s anglophone family history?