Honda GOLDWING GL1800/A 2015 Owner's Manual page 180

Engine Oil & Filter
Other viscosities shown in the following chart may be used when the average
temperature in your riding area is within the indicated range.
JASO T 903 standard
The JASO T 903 standard is an index for engine oils for 4-stroke motorcycle
engines.
There are two classes: MA and MB.
Oil conforming to the standard is labeled on the oil container. For example, the
following label shows the MA classification.
oil code
oil classification
177
Servicing Your Honda