This International Standard specifies requirements for the design, materials and testing of portable fuel systems with a rated capacity of 271 or less for carrying and storage of flammable liquids used for outboard motors installed on small craft with up to 24 m length of hull.
It does not apply to pressurized fuel systems.
BS ISO 13591:1997 history
1998BS ISO 13591:1998 Small craft. Portable fuel systems for outboard motors
1998BS ISO 13591:1997 Small craft - Portable fuel systems for outboard motors