Proposed standard for discovery
This is a proposed standard to make a calendar (.ics / iCalendar) discoverable from a web page. It's how you link a .ics file from a web page so it's easy to find by a computer.
If you found a website through duckduckgo, you also found the calendar. It's also a way to prove the ownership. We have different trusting relationships to website, this way the owner of the website is proven to also be the owner of the calendar.
If you add a link to an .ics/iCalendar file in the head section of your HTML page, you make the calendar discoverable publicly. Example:
<link rel="alternate" type="text/calendar" title="Your Title" href="https://linkto-site.com/ical-feed.ics">