Calendaring Extensions to WebDAV, or CalDAV, is an Internet standard allowing a client to access scheduling information on a remote server. It extends WebDAV ( HTTP-based protocol for data manipulation) specification and uses iCalendar format for the data. The access protocol is defined by RFC 4791. It allows multiple client access to the same information thus allowing cooperative planning and information sharing. Many server and client applications support the protocol. Extensions to CalDAV for automated scheduling are also standardized, as RFC 6638.