Used to indicate ownership of a small or independent business, not typically a large corporation. After retiring, my uncle became the proprietor of a small bookstore.
Pro Tip 2/3
Personal Identity
In small towns, being a proprietor often associates a person's identity closely with their business. The village knows Mrs. Smith as the proprietor of the only florist in town.
Pro Tip 3/3
Not an Employee
Remember, a proprietor is always an owner, never an employee of the business. He started as a chef but now is the proud proprietor of his own restaurant.