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<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<table summary="layout" width="66%" border="0" cellpadding="0" cellspacing="0"><tr><td><table summary="layout" width="100%" border="0" cellpadding="2" cellspacing="1">
<tr><td class="header">Internet Engineering Task Force</td><td class="header">S. Johnston</td></tr>
<tr><td class="header">Internet-Draft</td><td class="header">Australian Online Solutions</td></tr>
<tr><td class="header">Intended status: Experimental</td><td class="header">July 1, 2009</td></tr>
<tr><td class="header">Expires: January 2, 2010</td><td class="header"> </td></tr>
</table></td></tr></table>
<h1><br />Web Categories<br />draft-johnston-http-category-header-00</h1>
<h3>Status of this Memo</h3>
<p>
This Internet-Draft is submitted to IETF in full
conformance with the provisions of BCP 78 and BCP 79.</p>
<p>
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups.
Note that other groups may also distribute working documents as
Internet-Drafts.</p>
<p>
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.”</p>
<p>
The list of current Internet-Drafts can be accessed at
<a href='http://www.ietf.org/ietf/1id-abstracts.txt'>http://www.ietf.org/ietf/1id-abstracts.txt</a>.</p>
<p>
The list of Internet-Draft Shadow Directories can be accessed at
<a href='http://www.ietf.org/shadow.html'>http://www.ietf.org/shadow.html</a>.</p>
<p>
This Internet-Draft will expire on January 2, 2010.</p>
<h3>Copyright Notice</h3>
<p>
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.</p>
<p>
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your
rights and restrictions with respect to this document.</p>
<h3>Abstract</h3>
<p>This document specifies the Category header-field for HyperText
Transfer Protocol (HTTP), which enables the sending of taxonomy
information in HTTP headers.
</p><a name="toc"></a><br /><hr />
<h3>Table of Contents</h3>
<p class="toc">
<a href="#anchor1">1.</a>
Introduction<br />
<a href="#anchor2">1.1.</a>
Requirements Language<br />
<a href="#anchor3">2.</a>
Categories<br />
<a href="#anchor4">3.</a>
The Category Header Field<br />
<a href="#anchor5">3.1.</a>
Examples<br />
<a href="#IANA">4.</a>
IANA Considerations<br />
<a href="#anchor6">4.1.</a>
Category Header Registration<br />
<a href="#Security">5.</a>
Security Considerations<br />
<a href="#anchor7">6.</a>
Internationalisation Considerations<br />
<a href="#rfc.references1">7.</a>
References<br />
<a href="#rfc.references1">7.1.</a>
Normative References<br />
<a href="#rfc.references2">7.2.</a>
Informative References<br />
<a href="#app-html">Appendix A.</a>
Notes on use with HTML<br />
<a href="#anchor10">Appendix B.</a>
Notes on use with Atom<br />
<a href="#app-acknowledgements">Appendix C.</a>
Acknowledgements<br />
<a href="#app-history">Appendix D.</a>
Document History<br />
<a href="#app-issues">Appendix E.</a>
Outstanding Issues<br />
<a href="#rfc.authors">§</a>
Author's Address<br />
</p>
<br clear="all" />
<a name="anchor1"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.1"></a><h3>1.
Introduction</h3>
<p>A means of indicating categories for resources on the web has been
defined by Atom <a class='info' href='#RFC4287'>[RFC4287]<span> (</span><span class='info'>Nottingham, M. and R. Sayre, “The Atom Syndication Format,” December 2005.</span><span>)</span></a>. This document defines a
framework for exposing category information in the same format via HTTP
headers.
</p>
<p>The atom:category element conveys information about a category
associated with an entry or feed. A given atom:feed or atom:entry
element MAY have zero or more categories which MUST have a "term"
attribute (a string that identifies the category to which the entry or
feed belongs) and MAY also have a scheme attribute (an IRI that
identifies a categorization scheme) and/or a label attribute (a
human-readable label for display in end-user applications).
</p>
<p>Similarly a web resource may be associated with zero or more
categories as indicated in the Category header-field(s). These
categories may be divided into separate vocabularies or "schemes" and/or
accompanied with human-friendly labels.
</p>
<p>[[ Feedback is welcome on the ietf-http-wg@w3.org mailing list,
although this is NOT a work item of the HTTPBIS WG. ]]
</p>
<a name="anchor2"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.1.1"></a><h3>1.1.
Requirements Language</h3>
<p>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 BCP 14, <a class='info' href='#RFC2119'>[RFC2119]<span> (</span><span class='info'>Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.</span><span>)</span></a>, as scoped to those conformance targets.
</p>
<p>This document uses the Augmented Backus-Naur Form (ABNF) notation
of <a class='info' href='#RFC2616'>[RFC2616]<span> (</span><span class='info'>Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “Hypertext Transfer Protocol -- HTTP/1.1,” June 1999.</span><span>)</span></a>, and explicitly includes the
following rules from it: quoted-string, token. Additionally, the
following rules are included from <a class='info' href='#RFC3986'>[RFC3986]<span> (</span><span class='info'>Berners-Lee, T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic Syntax,” January 2005.</span><span>)</span></a>:
URI.
</p>
<a name="anchor3"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.2"></a><h3>2.
Categories</h3>
<p>In this specification, a category is a grouping of resources by
'term', from a vocabulary ('scheme') identified by an IRI <a class='info' href='#RFC3987'>[RFC3987]<span> (</span><span class='info'>Duerst, M. and M. Suignard, “Internationalized Resource Identifiers (IRIs),” January 2005.</span><span>)</span></a>. It is comprised of:</p>
<ul class="text">
<li>A "term" which is a string that identifies the category to which
the resource belongs.
</li>
<li>A "scheme" which is an IRI that identifies a categorization
scheme (optional).
</li>
<li>An "label" which is a human-readable label for display in
end-user applications (optional).
</li>
</ul>
<p>A category can be viewed as a statement of the form "resource is from
the {term} category of {scheme}, to be displayed as {label}", for
example "'Löwchen' is from the 'dog' category of 'animals', to be
displayed as 'Canine'".
</p>
<a name="anchor4"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.3"></a><h3>3.
The Category Header Field</h3>
<p>The Category entity-header provides a means for serialising one or
more categories in HTTP headers. It is semantically equivalent to the
atom:category element in Atom <a class='info' href='#RFC4287'>[RFC4287]<span> (</span><span class='info'>Nottingham, M. and R. Sayre, “The Atom Syndication Format,” December 2005.</span><span>)</span></a>.
</p>
<p>
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>Category = "Category" ":" #category-value
category-value = term *( ";" category-param )
category-param = ( ( "scheme" "=" <"> scheme <"> )
| ( "label" "=" quoted-string )
| ( "label*" "=" enc2231-string )
| ( category-extension ) )
category-extension = token [ "=" ( token | quoted-string ) ]
enc2231-string = <extended-value, see [RFC2231], Section 7>
term = token
scheme = URI</pre></div>
<p>Each category-value conveys exactly one category but there may be
multiple category-values for each header-field and/or multiple
header-fields per <a class='info' href='#RFC2616'>[RFC2616]<span> (</span><span class='info'>Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “Hypertext Transfer Protocol -- HTTP/1.1,” June 1999.</span><span>)</span></a>.
</p>
<p>Note that schemes are REQUIRED to be absolute URLs in Category
headers, and MUST be quoted if they contain a semicolon (";") or comma
(",") as these characters are used to separate category-params and
category-values respectively.
</p>
<p>The "label" parameter is used to label the category such that it can
be used as a human-readable identifier (e.g. a menu entry). Alternately,
the "label*" parameter MAY be used encode this label in a different
character set, and/or contain language information as per <a class='info' href='#RFC2231'>[RFC2231]<span> (</span><span class='info'>Freed, N. and K. Moore, “MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations,” November 1997.</span><span>)</span></a>. When using the enc2231-string syntax,
producers MUST NOT use a charset value other than 'ISO-8859-1' or
'UTF-8'.
</p>
<a name="anchor5"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.3.1"></a><h3>3.1.
Examples</h3>
<p>NOTE: Non-ASCII characters used in prose for examples are encoded
using the format "Backslash-U with Delimiters", defined in Section 5.1
of <a class='info' href='#RFC5137'>[RFC5137]<span> (</span><span class='info'>Klensin, J., “ASCII Escaping of Unicode Characters,” February 2008.</span><span>)</span></a>.
</p>
<p>For example:
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>Category: dog</pre></div>
<p>indicates that the resource is in the "dog" category.
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>Category: dog; label="Canine"; scheme="http://purl.org/net/animals"</pre></div>
<p>indicates that the resource is in the "dog" category, from the
"http://purl.org/net/animals" scheme, and should be displayed as
"Canine".
</p>
<p>The example below shows an instance of the Category header encoding
multiple categories, and also the use of <a class='info' href='#RFC2231'>[RFC2231]<span> (</span><span class='info'>Freed, N. and K. Moore, “MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations,” November 1997.</span><span>)</span></a> encoding to represent both non-ASCII
characters and language information.
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>Category: dog; label="Canine"; scheme="http://purl.org/net/animals",
lowchen; label*=UTF-8'de'L%c3%b6wchen";
scheme="http://purl.org/net/animals/dogs"</pre></div>
<p>Here, the second category has a label encoded in UTF-8, uses the
German language ("de"), and contains the Unicode code point \u'00F6'
("LATIN SMALL LETTER O WITH DIAERESIS").
</p>
<a name="IANA"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.4"></a><h3>4.
IANA Considerations</h3>
<a name="anchor6"></a><br /><hr />
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<a name="rfc.section.4.1"></a><h3>4.1.
Category Header Registration</h3>
<p>This specification adds an entry for "Category" in HTTP to the
Message Header Registry <a class='info' href='#RFC3864'>[RFC3864]<span> (</span><span class='info'>Klyne, G., Nottingham, M., and J. Mogul, “Registration Procedures for Message Header Fields,” September 2004.</span><span>)</span></a> referring to
this document:
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>Header Field Name: Category
Protocol: http
Status: standard
Author/change controller:
IETF (iesg@ietf.org)
Internet Engineering Task Force
Specification document(s):
[ this document ]</pre></div>
<a name="Security"></a><br /><hr />
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<a name="rfc.section.5"></a><h3>5.
Security Considerations</h3>
<p>The content of the Category header-field is not secure, private or
integrity-guaranteed, and due caution should be exercised when using
it.
</p>
<a name="anchor7"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<a name="rfc.section.6"></a><h3>6.
Internationalisation Considerations</h3>
<p>Category header-fields may be localised depending on the
Accept-Language header-field, as defined in section 14.4 of <a class='info' href='#RFC2616'>[RFC2616]<span> (</span><span class='info'>Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “Hypertext Transfer Protocol -- HTTP/1.1,” June 1999.</span><span>)</span></a>.
</p>
<p>Scheme IRIs in atom:category elements may need to be converted to
URIs in order to express them in serialisations that do not support
IRIs, as defined in section 3.1 of <a class='info' href='#RFC3987'>[RFC3987]<span> (</span><span class='info'>Duerst, M. and M. Suignard, “Internationalized Resource Identifiers (IRIs),” January 2005.</span><span>)</span></a>. This
includes the Category header-field.
</p>
<a name="rfc.references"></a><br /><hr />
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<a name="rfc.section.7"></a><h3>7.
References</h3>
<a name="rfc.references1"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc"> TOC </a></td></tr></table>
<h3>7.1. Normative References</h3>
<table width="99%" border="0">
<tr><td class="author-text" valign="top"><a name="RFC2119">[RFC2119]</a></td>
<td class="author-text"><a href="mailto:sob@harvard.edu">Bradner, S.</a>, “<a href="http://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>,” BCP 14, RFC 2119, March 1997 (<a href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2119.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2119.xml">XML</a>).</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2231">[RFC2231]</a></td>
<td class="author-text">Freed, N. and K. Moore, “<a href="http://tools.ietf.org/html/rfc2231">MIME Parameter Value and Encoded Word Extensions: Character
Sets, Languages, and Continuations</a>,” RFC 2231, November 1997.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2616">[RFC2616]</a></td>
<td class="author-text">Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, “<a href="http://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>,” RFC 2616, June 1999.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC3864">[RFC3864]</a></td>
<td class="author-text">Klyne, G., Nottingham, M., and J. Mogul, “<a href="http://tools.ietf.org/html/rfc3864">Registration Procedures for Message Header Fields</a>,” BCP 90, RFC 3864, September 2004.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC3986">[RFC3986]</a></td>
<td class="author-text">Berners-Lee, T., Fielding, R., and L. Masinter, “<a href="http://tools.ietf.org/html/rfc3986">Uniform Resource Identifier (URI): Generic Syntax</a>,” STD 66, RFC 3986, January 2005.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC3987">[RFC3987]</a></td>
<td class="author-text">Duerst, M. and M. Suignard, “<a href="http://tools.ietf.org/html/rfc3987">Internationalized Resource Identifiers (IRIs)</a>,” RFC 3987, January 2005.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC4287">[RFC4287]</a></td>
<td class="author-text">Nottingham, M. and R. Sayre, “<a href="http://tools.ietf.org/html/rfc4287">The Atom Syndication Format</a>,” RFC 4287, December 2005 (<a href="http://www.ietf.org/rfc/rfc4287.txt">TXT</a>, <a href="http://tools.ietf.org/html/rfc4287">HTML</a>).</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC5137">[RFC5137]</a></td>
<td class="author-text">Klensin, J., “<a href="http://tools.ietf.org/html/rfc5137">ASCII Escaping of Unicode Characters</a>,” RFC 5137, February 2008.</td></tr>
</table>
<a name="rfc.references2"></a><br /><hr />
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<h3>7.2. Informative References</h3>
<table width="99%" border="0">
<tr><td class="author-text" valign="top"><a name="OCCI">[OCCI]</a></td>
<td class="author-text">Open Grid Forum (OGF), Edmonds, A., Metsch, T., Johnston, S., and A. Richardson, “<a href="http://purl.org/occi">Open Cloud Computing Interface (OCCI)</a>.”</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2068">[RFC2068]</a></td>
<td class="author-text">Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T. Berners-Lee, “<a href="http://tools.ietf.org/html/rfc2068">Hypertext Transfer Protocol -- HTTP/1.1</a>,” RFC 2068, January 1997.</td></tr>
<tr><td class="author-text" valign="top"><a name="W3C.REC-html401-19991224">[W3C.REC-html401-19991224]</a></td>
<td class="author-text">Raggett, D., Hors, A., and I. Jacobs, “<a href="http://www.w3.org/TR/1999/REC-html401-19991224">HTML 4.01 Specification</a>.”</td></tr>
<tr><td class="author-text" valign="top"><a name="W3C.WD-html5-20090423">[W3C.WD-html5-20090423]</a></td>
<td class="author-text">Hyatt, D. and I. Hickson, “<a href="http://www.w3.org/TR/2009/WD-html5-20090423">HTML 5</a>,” April 2009.</td></tr>
<tr><td class="author-text" valign="top"><a name="draft-nottingham-http-link-header">[draft-nottingham-http-link-header]</a></td>
<td class="author-text">Nottingham, M., “<a href="http://www.ietf.org/internet-drafts/draft-nottingham-http-link-header-05.txt">Web Linking</a>,” draft-nottingham-http-link-header-05 (work in progress), April 2009 (<a href="http://www.ietf.org/internet-drafts/draft-nottingham-http-link-header-05.txt">TXT</a>).</td></tr>
<tr><td class="author-text" valign="top"><a name="rel-tag-microformat">[rel-tag-microformat]</a></td>
<td class="author-text">Çelik, T., Marks, K., and D. Powazek, “<a href="http://microformats.org/wiki/rel-tag">rel="tag" Microformat</a>.”</td></tr>
</table>
<a name="app-html"></a><br /><hr />
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<a name="rfc.section.A"></a><h3>Appendix A.
Notes on use with HTML</h3>
<p>In the absence of a dedicated category element in HTML 4 <a class='info' href='#W3C.REC-html401-19991224'>[W3C.REC‑html401‑19991224]<span> (</span><span class='info'>Raggett, D., Hors, A., and I. Jacobs, “HTML 4.01 Specification,” .</span><span>)</span></a> and HTML 5 <a class='info' href='#W3C.WD-html5-20090423'>[W3C.WD‑html5‑20090423]<span> (</span><span class='info'>Hyatt, D. and I. Hickson, “HTML 5,” April 2009.</span><span>)</span></a>, category information (including
user supllied folksonomy classifications) MAY be exposed using HTML A
and/or LINK elements by concatenating the scheme and term:
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>category-link = scheme term
scheme = URI
term = token</pre></div>
<p>These category-links MAY form a resolveable "tag space" in which case
they SHOULD use the "tag" relation-type per <a class='info' href='#rel-tag-microformat'>[rel‑tag‑microformat]<span> (</span><span class='info'>Çelik, T., Marks, K., and D. Powazek, “rel="tag" Microformat,” .</span><span>)</span></a>.
</p>
<p>Alternatively META elements MAY be used:
</p>
<p></p>
<ul class="text">
<li>where the "name" attribute is "keywords" and the "content"
attribute is a comma-separated list of term(s)
</li>
<li>where the "http-equiv" attribute is "Category" and the "content"
attribute is a comma-separated list of category-value(s)
</li>
</ul>
<a name="anchor10"></a><br /><hr />
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<a name="rfc.section.B"></a><h3>Appendix B.
Notes on use with Atom</h3>
<p>Where the cardinality is known to be one (for example, when
retrieving an individual resource) it MAY be preferable to render the
resource natively over HTTP without Atom structures. In this case the
contents of the atom:content element SHOULD be returned as the HTTP
entity-body and metadata including the type attribute and atom:category
element(s) via HTTP header-field(s).
</p>
<p>This approach SHOULD NOT be used where the cardinality is guaranteed
to be one (for example, search results which MAY return one result).
</p>
<a name="app-acknowledgements"></a><br /><hr />
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<a name="rfc.section.C"></a><h3>Appendix C.
Acknowledgements</h3>
<p>The author would like to thank Mark Nottingham for his work on Web
Linking <a class='info' href='#draft-nottingham-http-link-header'>[draft‑nottingham‑http‑link‑header]<span> (</span><span class='info'>Nottingham, M., “Web Linking,” April 2009.</span><span>)</span></a> (on
which this document was based) and to the authors of <a class='info' href='#RFC2068'>[RFC2068]<span> (</span><span class='info'>Fielding, R., Gettys, J., Mogul, J., Nielsen, H., and T. Berners-Lee, “Hypertext Transfer Protocol -- HTTP/1.1,” January 1997.</span><span>)</span></a> for specification of the Link: header-field on
which this is based.
</p>
<p>The author would like to thank members of the OGF's Open Cloud
Computing Interface <a class='info' href='#OCCI'>[OCCI]<span> (</span><span class='info'>Open Grid Forum (OGF), Edmonds, A., Metsch, T., Johnston, S., and A. Richardson, “Open Cloud Computing Interface (OCCI),” .</span><span>)</span></a> working group for their
contributions and others who commented upon, encouraged and gave
feedback to this draft.
</p>
<a name="app-history"></a><br /><hr />
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<a name="rfc.section.D"></a><h3>Appendix D.
Document History</h3>
<p>[[ to be removed by the RFC editor should document proceed to
publication as an RFC. ]]
</p>
<p></p>
<blockquote class="text">
<p>-00</p>
<ul class="text">
<li>Initial draft based on
draft-nottingham-http-link-header-05
</li>
</ul>
</blockquote>
<a name="app-issues"></a><br /><hr />
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<a name="rfc.section.E"></a><h3>Appendix E.
Outstanding Issues</h3>
<p>[[ to be removed by the RFC editor should document proceed to
publication as an RFC. ]]
</p>
<p>The following issues are oustanding and should be addressed:</p>
<ol class="text">
<li>Is extensibility of Category headers necessary as is the case for
Link: headers? If so, what are the use cases?
</li>
<li>Is supporting multi-lingual representations of the same
category(s) necessary? If so, what are the risks of doing so?
</li>
<li>Is a mechanism for maintaining Category header-fields required?
If so, should it use the headers themselves or some other
mechanism?
</li>
<li>Does this proposal conflict with others in the same space? If so,
is it an improvement on what exists?
</li>
</ol>
<a name="rfc.authors"></a><br /><hr />
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<h3>Author's Address</h3>
<table width="99%" border="0" cellpadding="0" cellspacing="0">
<tr><td class="author-text"> </td>
<td class="author-text">Sam Johnston</td></tr>
<tr><td class="author-text"> </td>
<td class="author-text">Australian Online Solutions</td></tr>
<tr><td class="author-text"> </td>
<td class="author-text">GPO Box 296</td></tr>
<tr><td class="author-text"> </td>
<td class="author-text">Sydney, NSW 2001</td></tr>
<tr><td class="author" align="right">Email: </td>
<td class="author-text"><a href="mailto:samj@samj.net">samj@samj.net</a></td></tr>
<tr><td class="author" align="right">URI: </td>
<td class="author-text"><a href="http://samj.net/">http://samj.net/</a></td></tr>
</table>
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