Network Working Group E. Pot Internet-Draft fruux GmbH Expires: December 29, 2016 June 27, 2016 CardDAV Address Book Sharing draft-pot-carddav-sharing-00 Abstract This specification defines sharing address books between users on a CardDAV server. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on December 29, 2016. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Pot Expires December 29, 2016 [Page 1] Internet-Draft CardDAV Address Book Sharing June 2016 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Conventions Used in This Document . . . . . . . . . . . . . . 2 3. Address book sharing . . . . . . . . . . . . . . . . . . . . 2 4. Handling multiple copies of a contact . . . . . . . . . . . . 2 5. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction Users of CardDAV [RFC6352] often require a mechanism to share an address book with other users. Sharing address books is for the most part completely implemented using draft-pot-webdav-resource-sharing, but there are a few considerations specific to CardDAV to ensure that certain mechanisms still behaves as expected. 2. Conventions Used in This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. When XML element types in the namespaces "DAV:" and "urn:ietf:params:xml:ns:caldav" are referenced in this document outside of the context of an XML fragment, the string "DAV:" and "CALDAV:" will be prefixed to the element type names respectively. 3. Address book sharing While the draft-pot-webdav-resource-sharing specification allows sharing of potentially any resource on a server, this specification only concerns itself with sharing address book collections, as defined in CardDAV [RFC6352]. Sharing of resources other than address book collections is not addressed in this specification. 4. Handling multiple copies of a contact vCard are often distributed via email, and two users of a CardDAV might have a copy of the same vCard. When those two users now share an addressbook, they might end up with two vCards that describe the same person. Pot Expires December 29, 2016 [Page 2] Internet-Draft CardDAV Address Book Sharing June 2016 Some address book user agents coalesce two vCards from different addressbooks to show up as one (merged) vCard to an end user. These clients SHOULD ensure that when an update is made to a merged vCard, all instances of that vCard are updated if the user agent has read- write access. In case two vCards have conflicting information, the information from the vCard with the highest value for the REV property should be used. 5. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, DOI 10.17487/RFC4791, March 2007, . [RFC6352] Daboo, C., "CardDAV: vCard Extensions to Web Distributed Authoring and Versioning (WebDAV)", RFC 6352, DOI 10.17487/RFC6352, August 2011, . [RFC7303] Thompson, H. and C. Lilley, "XML Media Types", RFC 7303, DOI 10.17487/RFC7303, July 2014, . Author's Address Evert Pot fruux GmbH Koenigsstrasse 32 Muenster, NRW 48143 Germany Email: me@evertpot.com URI: https://fruux.com/ Pot Expires December 29, 2016 [Page 3]