Glossary

webcal

A URL scheme (webcal://) that tells a device to subscribe to a calendar feed instead of just downloading it.

webcal:// is not a different protocol; it is a hint. The link points at an ordinary https ICS feed, but the webcal scheme tells Apple devices and some desktop apps to open their subscribe dialog rather than downloading the file once.

If an app does not understand webcal://, replacing webcal:// with https:// yields the same feed. That is why share pages often offer both a subscribe button and a copyable https feed link.