Final answer:
NRCan is primarily involved in the legal enforcement of trademarks and graphic identifiers, protecting them from unauthorized use.
Step-by-step explanation:
The role of NRCan (Natural Resources Canada) with respect to the use of trademarks and graphic identifiers is primarily legal enforcement. NRCan is responsible for ensuring that the Government of Canada's official symbols, including trademarks and graphic identifiers, are used properly and protected against unauthorized use. This includes monitoring for infringement issues, taking action against unauthorized use, and providing guidelines for proper usage to ensure the integrity and reputation of the Canadian government's branding is upheld.