The National Fire Protection Agency has adopted several new rules, which some states enacted effective January 1, 2017. North Carolina was one of those states. Others have and will follow. All pilots and crew chiefs should become familiar with the regulations. If you re-fuel in these states that have adopted these regs, you must comply.
One of these requirements is that propane tanks must be marked to advise they comply with FAA regulations.
Ken Draughn has stickers available for $1 which will help you meet this requirement. Contact Ken to get these stickers.
Want more information on the other points of the regulation? See this information written by CBA member, and former BFA president, Sam Parks.
http://www.hotairballooning.org/uploads/Education/Propane.txt