Card Distributed Authoring and Versioning (CardDAV)

CardDAV (short for Card Distributed Authoring and Versioning) is an address book client/server protocol designed to allow users to access and share contact data on a server.

The CardDAV protocol was developed by the IETF and has been published as RFC 6352 in August 2011.[1] CardDAV is based on WebDAV, which is based on HTTP, and it uses vCard for contact data.