NASSD (National Association of Sign Supply Distributors)
USSC (United States Sign Council)
ISA (International Sign Association)
CSA (California Sign Association)
WSA (World Sign Associates)
ISA (Illinois Sign Association)
NFPA (National Fire Protection Association) - NEC codes found here
Mid South Sign Association (www.midsouthsignassociation.org)
Southeast Sign Association (www.southeastsigns.org)
Florida Sign Association (www.floridasigns.org)
Virginia Sign Association (www.virginiasigns.org)
Texas Sign Association (www.txsigns.org)
Sign Association of Canada (www.sac-ace.ca)
UL's Sign Testing Website