CalDAV is described as "Calendaring Extensions to WebDAV" in [RFC 4791](https://datatracker.ietf.org/doc/html/rfc4791) and [RFC 7986](https://datatracker.ietf.org/doc/html/rfc7986) and the underlying iCal format is described at least in [RFC 5545](https://datatracker.ietf.org/doc/html/rfc5545). \
This library has been intensivley tested with Nextcloud servers. It should support Owncloud and iCloud as well, since they use the very same CalDAV protocol.
CalDAV is described as "Calendaring Extensions to WebDAV" in [RFC 4791](https://datatracker.ietf.org/doc/html/rfc4791) and [RFC 7986](https://datatracker.ietf.org/doc/html/rfc7986) and the underlying iCal format is described at least in [RFC 5545](https://datatracker.ietf.org/doc/html/rfc5545).