2.3. Updated Internet Drafts and Published RFCsNon-Gregorian Recurrence Rules in iCalendarSupport for iCalendar RelationshipsjCal: The JSON format for iCalendarUse of the Prefer Header Field in Web Distributed Authoring and Versioning (WebDAV)CalDAV Managed AttachmentsNew Properties for iCalendarjCard: The JSON format for vCard (now an IETF WG draft)