Before revision: For planetographic longitude, west longitudes (i.e., longitudes measured positively to the west) are used when the rotation is prograde, and eastward longitudes (i.e., longitudes measured positively to the east) when the rotation is retrograde.
After revision: For planetographic longitude, west longitudes (i.e., longitudes measured positively to the west) are used when the rotation is prograde, and east longitudes (i.e., longitudes measured positively to the east) when the rotation is retrograde.