During the mid-90s it became clear that the JASO Specifications cannot satisfy the requirements of the modern European two-stroke engines. The ISO standards listed below were developed to address this shortcoming. Their basis is the relevant JASO standard + they require an additional 3h Honda test to be run to quantify piston cleanliness and detergent effect.
Theo Mang, Wilfried Dresel: Lubricants and Lubrication has more on this subject.