Article L145-47 of the French Commercial code
The tenant may add related or complementary activities to the business provided for in the lease. To this end, he must make his intention known to the landlord by extrajudicial act or by registered letter with acknowledgement of receipt, indicating the activities whose exercise is envisaged. This formality serves as formal notice to the owner to make known within two months, on pain of forfeiture, whether he disputes the related…