Learning → Cohorts lists cohorts for courses set to Cohort delivery. The New cohort button stays disabled until at least one course is in cohort mode. A course is either self-paced or cohort, never both, and a public enrollment in a cohort course must choose a cohort.
Dates
Starts on, Ends on, Enrollment opens, Enrollment closes. Ends must be after starts and closes after opens. A blank opens date means open now; a blank closes date means enrolment closes at the start date. Relative drip lessons count from the cohort start.
Capacity
Optional; blank is unlimited. Seats count both Pending payment and Active enrollments.
Deleting
A cohort that has any enrollment bound to it cannot be deleted. (The old confirmation text said students would be un-bound; it now says deletion is refused.)