Difference between revisions of "vcard-errata"

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(3.6.7 UID Type Definition - no IANA registered identifier formats found)
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In the development of [[hcard|hCard]] and proxies like X2V, we have discovered various details of RFC 2426 vCard that appear to be mistakes.  Thus we are documenting them here as we find them, organized by RFC 2426 section number.
 
In the development of [[hcard|hCard]] and proxies like X2V, we have discovered various details of RFC 2426 vCard that appear to be mistakes.  Thus we are documenting them here as we find them, organized by RFC 2426 section number.
  
; Author(s): Tantek Çelik
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; Editor: Tantek Çelik
  
 
== Errata ==
 
== Errata ==
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=== 2.2 Predefined Type Parameter Usage ===
 
=== 2.2 Predefined Type Parameter Usage ===
  
# 2005-11-24 by [http://tantek.com/log/ Tantek Çelik]
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# 2005-11-24 by [http://tantek.com/ Tantek Çelik]
  
 
Just after this block:
 
Just after this block:
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</nowiki></pre>
 
</nowiki></pre>
  
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=== 3.6.7 UID Type Definition ===
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# 2007-09-08 by [http://tantek.com/ Tantek Çelik] based on [http://microformats.org/wiki?title=uid&diff=21212&oldid=21211 issue raised by Andy Mabbett 11:10, 7 Sep 2007].
 +
 +
[[RFC2426]] says [note inserted text for clarification].
 +
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<pre><nowiki>
 +
  The [UID] type can include the type parameter "TYPE" to specify the format
 +
  of the identifier. The TYPE parameter value should be an IANA
 +
  registered identifier format. The value can also be a non-standard
 +
  format.
 +
</nowiki></pre>
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 +
Note that a search of the IANA website as of 11:10, 7 Sep 2007 finds no occurrences of "identifier format", therefore there is no way to comply with the "should" sentence in the above-quoted portion of section 3.6.7.  Since the statement is only a "should", thus content {{may}} ignore it, and there is no way to comply with the "should", it the simplest errata is to drop the impossible "should" statement, and remove the word "also" from the following sentence, as follows:
 +
 +
<pre><nowiki>
 +
  The [UID] type can include the type parameter "TYPE" to specify the format
 +
  of the identifier. The value can be a non-standard format.
 +
</nowiki></pre>
  
 
=== 5.  Differences From vCard v2.1 ===
 
=== 5.  Differences From vCard v2.1 ===
  
# 2005-11-24 by [http://tantek.com/log/ Tantek Çelik]
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# 2005-11-24 by [http://tantek.com/ Tantek Çelik]  
  
RFC 2426 says:
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[[RFC2426]] says:
  
 
<pre><nowiki>
 
<pre><nowiki>
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</nowiki></pre>
 
</nowiki></pre>
  
We believe this to have been a mistake, note in particular that section 1. of RFC 2426 explicitly states that the CHARSET parameter is one of the "Predefined MIME Directory parameters" that is "used".  We believe that statement in section 1. of RFC 2426 to be '''correct'''.
+
We believe this to have been a mistake, note in particular that section 1. of [[RFC2426]] explicitly states that the CHARSET parameter is one of the "Predefined MIME Directory parameters" that is "used".  We believe that statement in section 1. of [[RFC2426]] to be '''correct'''.
  
 
The most obvious proof of why this is needed is when a vCard .vcf file is stored on and retrieved from  a local file-system, you obviously cannot depend on the Content-Type MIME (or HTTP) header field, nor can you assume that the operating system will keep character set metadata about the file in some other location.
 
The most obvious proof of why this is needed is when a vCard .vcf file is stored on and retrieved from  a local file-system, you obviously cannot depend on the Content-Type MIME (or HTTP) header field, nor can you assume that the operating system will keep character set metadata about the file in some other location.

Revision as of 00:52, 9 September 2007

vCard errata

In the development of hCard and proxies like X2V, we have discovered various details of RFC 2426 vCard that appear to be mistakes. Thus we are documenting them here as we find them, organized by RFC 2426 section number.

Editor
Tantek Çelik

Errata

2.2 Predefined Type Parameter Usage

  1. 2005-11-24 by Tantek Çelik

Just after this block:

   The vCard MIME Directory Profile uses the following predefined type
   parameters as defined by [MIME-DIR].

insert this:

        - CHARSET


just before this:

        - LANGUAGE


3.6.7 UID Type Definition

  1. 2007-09-08 by Tantek Çelik based on issue raised by Andy Mabbett 11:10, 7 Sep 2007.

vCard RFC 2426 says [note inserted text for clarification].

   The [UID] type can include the type parameter "TYPE" to specify the format
   of the identifier. The TYPE parameter value should be an IANA
   registered identifier format. The value can also be a non-standard
   format.

Note that a search of the IANA website as of 11:10, 7 Sep 2007 finds no occurrences of "identifier format", therefore there is no way to comply with the "should" sentence in the above-quoted portion of section 3.6.7. Since the statement is only a "should", thus content MAY ignore it, and there is no way to comply with the "should", it the simplest errata is to drop the impossible "should" statement, and remove the word "also" from the following sentence, as follows:

   The [UID] type can include the type parameter "TYPE" to specify the format
   of the identifier. The value can be a non-standard format.

5. Differences From vCard v2.1

  1. 2005-11-24 by Tantek Çelik

vCard RFC 2426 says:

        . The [VCARD] CHARSET type parameter has been eliminated.
          Character set can only be specified on the CHARSET parameter
          on the Content-Type MIME header field.

We believe this to have been a mistake, note in particular that section 1. of vCard RFC 2426 explicitly states that the CHARSET parameter is one of the "Predefined MIME Directory parameters" that is "used". We believe that statement in section 1. of vCard RFC 2426 to be correct.

The most obvious proof of why this is needed is when a vCard .vcf file is stored on and retrieved from a local file-system, you obviously cannot depend on the Content-Type MIME (or HTTP) header field, nor can you assume that the operating system will keep character set metadata about the file in some other location.

Thus it is critical that the CHARSET parameter be reused from MIME-DIR. This requires:

  1. delete the above quoted bullet item from section 5.
  2. make the change to section 2.2 as noted above.

See Also