SIS Import Format Documentation (https://canvas.instructure.com/doc/api/file.sis_csv.html) indicates that either course_id or section_id is required in enrollments.csv to identify the course for the enrollment. If course_id is specified, but not section_id, the "default" section of the course will be used.
It is unclear how Instructure defines or identifies a Canvas course's "default" section. Naturally, if a course contains only one section, that section is the default. However, suppose a course contains multiple sections. How can the default section be identified? If the default section is the first section in the course to be created, what becomes the default section if that first section is deleted?
The request in this idea is for an indicator to be available both in the UI and API to identify a course's default section.
In the UI, this could be manifested by adding a star (*) next to the default section in the Course Sections list when navigating to a course > Settings > Sections.
In the API, this field could be added to the course object and called "default_section_id". It would be included when getting a specific course (GET /api/v1/courses/:id).