Subscription token
A subscription token is the secret value embedded in a personal ICS feed URL. The token identifies you to the server — anyone who has the URL can read your bookings, so the token is a credential and should be treated like a password.
Each member has at most one active subscription token at a time. Regenerating the link on the Bookings tab’s Subscribe sheet invalidates the previous token immediately. Any calendar app still using the old URL stops receiving updates and must be re-subscribed.
Regenerate the token if you have ever posted your ICS URL in chat, a screenshot, or a support ticket.