[VCARDDAV] Proposal for new VCARD OBJECTCLASS property

Mike Douglass <mikeadouglass@gmail.com> Sun, 04 November 2012 05:26 UTC

Return-Path: <mikeadouglass@gmail.com>
X-Original-To: vcarddav@ietfa.amsl.com
Delivered-To: vcarddav@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id 7326621F960C; Sat, 3 Nov 2012 22:26:00 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.598
X-Spam-Status: No, score=-5.598 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, GB_I_INVITATION=-2, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id Ugk8LfrTHtgF; Sat, 3 Nov 2012 22:25:59 -0700 (PDT)
Received: from mail-qa0-f44.google.com (mail-qa0-f44.google.com []) by ietfa.amsl.com (Postfix) with ESMTP id 73B7221F9481; Sat, 3 Nov 2012 22:25:59 -0700 (PDT)
Received: by mail-qa0-f44.google.com with SMTP id 25so1600867qao.10 for <multiple recipients>; Sat, 03 Nov 2012 22:25:59 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject :content-type; bh=NtS+ohssWJyvl/VrBWIXAEMMznEQhtgauu6C3xJ2rf0=; b=w5hvAP0xPTJgyCNA8zTbehBEysECNiTjeB0rhl4bHIHdE2SxSRxkbTTXiGXjUmLJR9 OzzY8thoaXaVxHDNnCjZemS2ZB7jTPrLfYpORsRzQAWsZn03BVmEwxO2aN8CfZsDq7T5 DOhehmEwJbK90728RuKd1AogrndXvrP6mzJ4QP09Fxi6A3jnkuQdze6E6c+dHqqu2/Wy 9Sw1BQK5RhpinDTk0PgHHN2BGSHqvx2273FAfcZTPsisBXVNAO19xZV26VE3yEhy0EpW uw0ub8p39o4VdSTs6uM2TvcpepFFTOSgHPAnfL+zWcjjSDp7/SdUdFAPL2is7JLYVFtY lkdw==
Received: by with SMTP id t20mr10729521qeq.26.1352006758874; Sat, 03 Nov 2012 22:25:58 -0700 (PDT)
Received: from [] (cpe-74-76-210-192.nycap.res.rr.com. []) by mx.google.com with ESMTPS id i9sm2555143qak.3.2012. (version=SSLv3 cipher=OTHER); Sat, 03 Nov 2012 22:25:58 -0700 (PDT)
Message-ID: <5095FC65.2080803@gmail.com>
Date: Sun, 04 Nov 2012 01:25:57 -0400
From: Mike Douglass <mikeadouglass@gmail.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121011 Thunderbird/16.0.1
MIME-Version: 1.0
To: IETF Calsify <calsify@ietf.org>, CardDAV <vcarddav@ietf.org>
Content-Type: multipart/alternative; boundary="------------070204090402090402030604"
Subject: [VCARDDAV] Proposal for new VCARD OBJECTCLASS property
X-BeenThere: vcarddav@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: IETF vcarddav wg mailing list <vcarddav.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/vcarddav>, <mailto:vcarddav-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/vcarddav>
List-Post: <mailto:vcarddav@ietf.org>
List-Help: <mailto:vcarddav-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/vcarddav>, <mailto:vcarddav-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 04 Nov 2012 05:26:00 -0000

During discussions on the new vcard resource draft 
http://tools.ietf.org/html/draft-cal-resource-vcard-01 it seemed that we 
had significant overlap with the device specification


  and also applications:


We also realized we have a subset of properties which could apply to any 
schedulable entity, e.g. autoschedule, booking window, calendar user 
addresss (cua) and so on.

We propose a new, multiply occurring property: OBJECTCLASS.

A vcard containing one or more occurrences of this property MUST conform 
to the related specification. So for example we might have


The appearance of this property and value requires that the cua be 
present but it also allows us to apply appropriate defaults when a 
property is absent. For example, our resource draft states that the 
absence of the AUTOSCHEDULE property implies that invitations are 
automatically accepted.

A further advantage is that it seems to facilitate mapping from ldap to 
vcard. There are many widely used ldap object classes which it would be 
useful to make visible in vcard.

It enables authors of specifications to worry less about areas in which 
they are not expert. Any entity which is schedulable can be made so 
simply by adding OBJECTCLASS: SCHEDULABLE to the entity (and any 
appropriate properties).

It also avoids trying to resolve strict hierarchies of 'thing'. A device 
is a resource but so is a room and both may or may not be schedulable.

This proposal does not appear to conflict with the current 
specifications. It does however appear to offer a way to enhance the 
usability of vcards and provide consumers of the information with the 
assurance that it was generated correctly.


Mike Douglass douglm@rpi.edu
Senior Systems Programmer
Communication & Collaboration Technologies      518 276 6780(voice) 2809
Rensselaer Polytechnic Institute 110 8th Street, Troy, NY 12180