The National Independent Flag Dealers Association
The National Independent Flag Dealers Association is an organization of flag and banner retailers and manufacturers located throughout the United States.
https://www.nifda.net/
North American Vexillological Association
NAVA is a scholarly, non-profit, volunteer organization dedicated to the pursuit of Vexillology, the scientific study of flag history and symbolism. Its members come from all fields of vexillology, including flag collectors and historians, government officials, museum directors, flag dealers and manufacturers, writers, designers, and teachers, as well as those interested in flags as a hobby.
https://www.nava.org/