The calendar co-sponsorship function identifies an event as co-sponsored by multiple organizations. It also places the event in feeds and subscriptions for each sponsoring organization.
To create a co-sponsored event, your event must first be published to the calendar. When logged in to the calendar system, navigate to the event detail page, scroll down to "Request a Co-Sponsorship," select the group you want to co-sponsor the event with, and submit the request. Please note that only organizations that have created calendar groups are available to co-sponsor.
The owner(s) of that group will receive an email notification of the request, which they can approve or deny.
If another group requests a co-sponsorship with your group, the owner(s) of your group will receive the request notification.