How to disable syncing from your website
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This information is intended for site administrators.
If your site hosts calendars, then users can export your events via the iCalendar format to their own Yandex Calendar. After adding events, the Yandex Calendar robot will begin periodically downloading updates from your website and sync them with the user's Yandex Calendar.
The Yandex Calendar robot ignores the rules in the robots.txt file for undefined web crawlers (User-agent: *). If you want to restrict access to your website for the Yandex Calendar robot, then add this special rule to robots.txt:
User-agent: YandexCalendar
Disallow: /*.ics$
Once it's done, events in your calendar will no longer sync with your users' calendars.
Read more about robots.txt and how to use Yandex robots in Using robots.txt.