Enumerations: courseMode <CourseMode>, courseDigitalFormat <CourseDigitalFormat>, accessibilityPhysicalFeature <AccessibilityPhysicalFeature>
Schema course extend Re: The subject of a course.
schema course extend: dates of a course
schema-course-extend: Identifying the instructor of a course.
Last message date: Saturday, 21 May 2016 15:22:51 UTC