PICS 26.9 KB

Raw Blame History Permalink

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
    "http://www.w3.org/TR/html401/loose.dtd">
<html lang="en">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
  <meta http-equiv="PICS-Labels"
  content='(PICS-1.1 "http://www.rsac.org/ratingsv01.html" l by "martinm@raleigh.ibm.com" on "1996.06.24T10:11-0500" exp "1998.06.06T08:00-0500" r (n 0 s 0 v 0 l 0))'>
  <meta http-equiv="PICS-Label"
  content='(PICS-1.1 "http://www.classify.org/safesurf/" l by "martinm@raleigh.ibm.com"  on "1996.06.24T15:38-0500" exp "1998.06.06T08:00-0500" r (SS~~000 1))'>
  <title>Platform for Internet Content Selection (PICS)Platform for Internet
  Content Selection (PICS)</title>
  <!-- Embedded PICS rating using RSACi. This page has no sex, violence, bad language, nor nudity. -->
  <meta http-equiv="PICS-Labels"
  content='(PICS-1.1 "http://www.rsac.org/ratingsv01.html" l by "martinm@raleigh.ibm.com" on "1996.06.24T10:11-0500" exp "1997.06.06T08:00-0500" r (n 0 s 0 v 0 l 0))'>
  <!-- Embedded PICS rating using SafeSurf. This page is acceptable for all ages. -->
  <meta http-equiv="PICS-Label"
  content='(PICS-1.1 "http://www.classify.org/safesurf/" l by "martinm@raleigh.ibm.com"  on "1996.06.24T15:38-0500" exp "1997.06.06T08:00-0500" r (SS~~000 1))'>
  <!-- Changed by: Paul Resnick, 24-Dec-1997 -->
  <link rev="made" href="mailto:pics-ask@w3.org">
  <!-- Embedded PICS rating using RSACi. This page has no sex, violence, bad language, nor nudity. -->
  <!-- Embedded PICS rating using SafeSurf. This page is acceptable for all ages. -->
  <style type="text/css">
   BODY { color: black; background: white }
   .header-example { margin-left: 2em }</style>
</head>

<body>
<p><a href="../"><img src="../Icons/WWW/w3c_home" alt="W3C"
border="0"></a></p>

<h1><img alt="PICS" src="../Icons/WWW/pics_69x112_8g" align="top">
 Platform for Internet Content Selection (PICS)</h1>


<div style="border: solid thick red; padding: 1em"><p>This document is not currently maintained as PICS
has been superseded by the Protocol for Web Description Resources (<a href="/2007/powder/">POWDER</a>). W3C encourages authors and
implementors to refer to POWDER (or its successor) rather than PICS when developing systems to describe Web content or agents to
act on those descriptions. A brief document outlining the advantages offered by POWDER compared with PICS is <a href="/2009/08/pics_superseded.html">available
separately</a>. The <a href="http://www.w3.org/standards/techs/pics" title="PICS Current Status Page">Current Status Page</a> lists
the PICS Recommendations and in each case includes a link to the document that supersedes it.</p>
<p>Contact details of the individuals named below and links to other documents may no longer be active.</p>
</div>


<p>The <b>PICS</b><a
href="http://www.w3.org/Consortium/Legal/ipr-notice.html#W3C Trademarks"><font
color="#FF0000"><sup><sup>TM</sup></sup></font></a> specification enables
labels (metadata) to be associated with Internet content. It was originally
designed to help parents and teachers control what children access on the
Internet, but it also facilitates other uses for labels, including code
signing and privacy. The PICS platform is one on which other rating services
and filtering software have been built.</p>

<h2>Table of Contents</h2>
<ul>
  <li><a href="#Introduction">Introduction</a></li>
  <li><a href="#Participating">Participating</a></li>
  <li><a href="#New">What's New</a></li>
  <li><a href="#Media">Media information</a></li>
  <li><a href="#links">What Governments, Media, and Individuals are Saying
    about PICS (pro and con)</a></li>
  <li><a href="#Specs">Technical Specifications</a></li>
  <li><a href="#Developers">Resources for developers of software and labeling
    services</a></li>
  <li><a href="#Products">Lists of PICS-compatible products and
  services</a></li>
  <li><a href="defaults.html">Hints on self-labeling</a></li>
  <li><a href="#Innovations">Innovative uses of PICS labels</a></li>
  <li><a href="#RDF">RDF</a></li>
</ul>

<h2>See also</h2>
<ul>
  <li><a href="http://www.w3.org/2000/03/PICS-FAQ">PICS Frequently Asked
    Questions</a></li>
</ul>

<h2>_________</h2>

<p> </p>

<h2><a name="Introduction">Introduction</a></h2>

<p>For introductory materials, we suggest:</p>
<ul>
  <li><a href="principles.html">PICS Statement of Principles</a> and <a
    href="http://www.w3.org/TR/NOTE-PICS-Statement">Statement on Using PICS
    Well</a>.</li>
  <li><a href="http://www.research.att.com/~lorrie/pubs/tech4kids/">Technology
    Inventory</a>. Lorrie Cranor and Paul Resnick.</li>
  <li><a href="http://www.sciam.com/0397issue/0397resnick.html">Filtering
    Information on the Internet</a> [broken link as of July 2005].
    Paul Resnick. <i>Scientific American</i>,
    March 1997, pp. 106-108.</li>
  <li><a href="iacwcv2.htm">PICS: Internet Access Controls Without
    Censorship</a>, Paul Resnick and Jim Miller, <i>Communications of the
    ACM</i>, 1996, vol. 39(10), pp. 87-93.</li>
  <li><a href="PICS-FAQ-980126.html">PICS and Intellectual Freedom FAQ.</a>
    Paul Resnick.</li>
</ul>

<h2><a name="Participating">Participating</a></h2>

<p>W3C maintains two electronic mailing lists for public use:</p>
<ul>
  <li><a name="pics-info"></a><b>PICS-info@w3.org</b> is where we distribute
    public announcements related to the PICS project. Anyone may subscribe by
    sending email to <b>PICS-info-request@w3.org</b> with the word "Subscribe"
    in the Subject: field.</li>
  <li><b>PICS-ask@w3.org</b> is for the public to send questions about the
    PICS project.</li>
</ul>

<p>PICS also maintains special purpose <a href="#Developers">mailing lists for
developers</a>. There is also a <a href="IG/">PICS Interest Group</a> for W3C
members and invited participants.</p>

<div style="border: solid thick red; padding: 1em"><p>The PICS Interest Group and mailing lists have now been closed but
archives remain available:</p><ul>
<li><a href="http://lists.w3.org/Archives/Public/pics-info/">PICS Info</a></li>
<li><a href="http://lists.w3.org/Archives/Public/pics-interest/">PICS Interest</a></li>
</ul></div>


<h2>What's <a name="New">New</a></h2>
<ul>
  <li><a href="http://www.w3.org/TR/rdf-pics">PICS Rating Vocabularies in
    XML/RDF</a> (W3C NOTE 27 March 2000)</li>
  <li><a href="http://www.w3.org/TR/NOTE-PICS-Statement">Statement on Using
    PICS Well</a> (1 June 1998)</li>
  <li><a href="http://www.w3.org/TR/REC-DSig-label/">PICS Signed Labels (DSig)
    1.0 Specification</a> (27 May 1998)</li>
  <li><a href="refcode/Overview.html">PICS Reference Code</a> (2/98)</li>
  <li><a href="http://www.w3.org/TR/REC-PICSRules">PICSRules Language for
    Writing Filtering Rules</a>; a W3C <a
    href="http://www.w3.org/Consortium/Process">Recommendation</a>
  (12/97)</li>
  <li><a
    href="http://www.w3.org/Policy/Documents/TBLGILC_Response.html">Letter
    from Tim Berners-Lee to GILC</a> about PICSRules. Tim Berners-Lee
  (12/97)</li>
  <li><a href="PICS-FAQ-980126.html">PICS and Intellectual Freedom FAQ.</a>
    Paul Resnick. Updated filtering section to include brief discussion of
    PICSRules. (updated 1/97)</li>
  <li><a
    href="http://www.w3.org/People/Reagle/stuff/PICSRules_Response.html">PICSRules
    and Free Speech.</a> Joseph Reagle. General comments and Joseph's
    responses to posts on the fight-censorship mailing list. (12/97)</li>
  <li>Free <a href="refcode/Parser/">Java implementation</a> of parsers for
    PICS labels, services, and rules, evaluator for PICSRules (12/97)</li>
  <li><a href="http://www.w3.org/TR/PR-DSig-label">DSIG 1.0 specification for
    signing PICS labels</a>; a W3C <a
    href="http://www.w3.org/Consortium/Process">Proposed Recommendation</a>
    (12/97)</li>
  <li><a href="http://www.surfwatch.com">SurfWatch</a> available in PICS
    format.  <a href="http://www.si.umich.edu/~presnick/PICS-incubator/">The
    PICS Application Incubator</a> [broken link as of March 2005] at The University of Michigan School of
    Information created a PICS label bureau to distribute SurfWatch
    labels. (12/97)</li>
  <li><a href="http://www.ics.raleigh.ibm.com/WebTrafficExpress">IBM's
    PICS-compliant proxy server</a> released (12/97)</li>
  <li><a href="http://www.netshepherd.com">Net Shepherd and Alta Vista offer
    filtered Internet search</a> (11/97)
    [broken link as of July 2005]</li>
</ul>

<h2>Information for the <a name="Media">Media</a></h2>

<p>For inquiries about PICS, please refer to
<a href="../Consortium/contact.html#press">W3C's press contact
information</a>.</p>

<p>Please direct technical inquiries to:</p>
<ul>
  <li><a href="mailto:pics-ask@w3.org">W3C PICS expert</a>,
  (pics-ask@w3.org)</li>
  <li><a href="mailto://swick@w3.org">Ralph R. Swick</a>, (<a
    href="mailto:swick@w3.org">swick@w3.org</a>), W3C metadata lead. +
    1.617.253.2613</li>
</ul>

<p>Inquiries about public policy issues surrounding content regulation may
also be directed to</p>
<ul>
  <li><a href="mailto://reagle@w3.org">Joseph Reagle</a> (<a
    href="mailto://reagle@w3.org">reagle@w3.org</a>), W3C Policy Analyst. +
    1.617.253.2613</li>
  <li><a href="mailto:djweitzner@w3.org">Danny Weitzner</a>, (<a
    href="mailto:djweitzner@w3.org">djweitzner@w3.org</a>), W3C Technology and
    Society Domain Leader. + 1.617.253.2613</li>
</ul>

<h2><a name="links"></a>What others are saying about PICS</h2>

<h3>Governments</h3>
<ul>
  <li><a
    href="http://www.europarl.eu.int/dg1/a4/en/a4-97/a4-0098.htm">European
    Commission Report (follow-on document of 20 March, 1997)</a></li>
  <li><a href="http://www.aba.gov.au/what/online/index.htm">Australian
    Broadcast Authority report on its investigation into on-line
  services</a></li>
  <li><a
    href="http://europa.eu.int/en/record/green/gp9610/protec.htm">European
    Parliament Green Paper: the Protection of Minors and Human Dignity in
    Audiovisual and Information Services</a></li>
  <li><a href="http://europa.eu.int/en/record/legal/index.htm">European Union
    Communication on illegal and harmful content on the Internet</a>
    [broken link as of July 2005]</li>
  <li><a href="http://www2.echo.lu/legal/en/internet/content/wpen.html">Report
    of European Commission Working party on illegal and harmful content on the
    internet</a> [broken link as of July 2005]</li>
  <li><a href="http://www2.echo.lu/best_use/best_use.html">European Commission
    Forum for Exchange of Information on Internet Best Practices</a>
    [broken link as of July 2005]</li>
</ul>

<h3>Media</h3>
<ul>
  <li><a href="http://www.wired.com/news/news/technology/story/9176.html">PICS
    Walks Fine Line on Net Filtering</a></li>
  <li><a
    href="http://www.hotwired.com/packet/garfinkel/97/05/index2a.html">Good
    Clean PICS: The most effective censorship technology the Net has ever seen
    may already be installed on your desktop</a>(Simson Garfinkel in HotWired:
    February 1997)</li>
  <li><a href="http://www.collegehill.com/ilp-news/reagle.html">College Hill
    interview with Joseph Reagle, W3C staff member</a>
    [broken link as of July 2005]</li>
</ul>

<h3>Individuals and Organizations</h3>
<ul>
  <li><a href="http://www.eff.org/policies/filtration_policy.html">EFF's Draft
    Policy on public interest principles for online filtration, ratings, and
    labeling systems</a> [broken link as of July 2005].
    Suggested guidelines for responsible use of labeling
    and filtering.</li>
  <li><a href="http://www.bluehighways.com/tifap/">The Internet Filter
    Assessment Project.</a> A group of librarians with mixed feelings about
    filtering examined several products in detail and discussed the issues
    facing libraries.</li>
  <li><a href="http://www.aclu.org/issues/cyber/burning.html">ACLU White Paper
    Critical of Labeling and Filtering</a>
    [broken link as of July 2005]</li>
  <li><a href="http://www.irdu.nus.sg/~wayne/paper.html">PICS-Aware Proxy
    System vs. Proxy Server Filters.</a>
    [broken link as of July 2005] Wayne Salamonsen and Roland Yeo,
    proceedings of INET '97.</li>
  <li><a href="http://www.ariadne.ac.uk/issue9/pics/">Metadata, PICS and
    Quality.</a> Chris Armstrong. Ariadne magazine, May 1997.</li>
  <li><a href="http://www.msen.com/~weinberg/rating.htm">Rating the Net</a>.
    Jonathan Weinberg. in Hasting Communications and Entertainment Law
    Journal, Vol. 19, No. 2, p. 453-482. (A balanced but critical academic's
    look at rating systems and their legal and social impact.)</li>
  <li><a href="http://www.pobox.com/~rene/liberty/label.html">The Net Labeling
    Delusion</a> (anti-PICS web site in Australia)</li>
  <li><a href="http://www.eff.org/~declan/fight-censorship/">Fight-censorship
    mailing lists</a> [broken link as of July 2005]
    (Declan McCullagh's moderated and unmoderated lists;
    occasional discussion of PICS and related technologies).</li>
</ul>

<h2>__________</h2>

<h2><a name="Specs">PICS Technical Specifications</a></h2>

<h3>Completed Specifications for PICS-1.1</h3>

<p>These are official W3C recommendations. They are stable.  The normative
specifications are in English.  <a href="translations">Translations</a> of
some of these are available.</p>
<ol>
  <li><a href="http://www.w3.org/TR/REC-PICS-services"><strong><em>Service
    descriptions</em></strong>:</a> Specifies the format for describing a
    rating service's vocabulary and scales; analogous to a database
  schema.</li>
  <li><em><a href="http://www.w3.org/TR/REC-PICS-labels"><strong>Label format
    and distribution</strong>:</a></em> Specifies the format of labels and
    methods for distributing both self-labels and third-party labels.</li>
  <li><strong><em><a
    href="http://www.w3.org/TR/REC-PICSRules">PICSRules:</a></em></strong>
    Specifies an interchange format for filtering preferences, so that
    preferences can be easily installed or sent to search engines.</li>
</ol>
<ol start="4">
  <li><b><i><a href="http://www.w3.org/TR/REC-DSig-label/">PICS Signed Labels
    (DSig) 1.0 Specification</a></i></b><a
    href="http://www.w3.org/TR/PR-DSig-label">:</a> Specifies the syntax and
    semantics of digital signatures in PICS labels.</li>
</ol>

<h3>Special Supplements to the Specifications</h3>

<p>These are not official W3C recommendations, but they do represent a
consensus of the PICS working group.</p>
<ol start="5">
  <li><a href="defaults.html">Default and Override Labels:</a> Specifies what
    a user agent (e.g., filtering software) should do when multiple labels are
    available from the same service; Also suggests where filtering agents
    should look for self-labels if they do not arrive in or along-with a
    document.</li>
</ol>

<h2><a name="Developers"></a></h2>

<h2>Resources for Developers of Software and Labeling Services</h2>

<p>There is a low-volume mailing list, pics-interest@w3.org for developers and
potential developers of PICS related products and services. To join this list,
send email to pics-ask@w3.org and say why you're interested in joining. </p>

<h3>Resources for Software Developers</h3>

<p>The <a href="#Specs">technical specifications</a> above are the most
important resource for developers. In addition:</p>
<ul>
  <li>Free <a href="refcode/Parser/">Java implementation</a> of parsers for
    PICS labels, services, and rules, evaluator for PICSRules</li>
  <li><a href="http://www.w3.org/PICS/refcode/PICSLE/">PICSLE</a>, the PICS
    Label Editor, also written in Java, provided courtesy of  <i><a
    href="http://www.watson.ibm.com/">IBM T.J. Watson Research
  Center.</a></i></li>
  <li><a href="http://www.ics.raleigh.ibm.com/WebTrafficExpress">IBM's
    PICS-compliant proxy server</a> makes it easy to set up a label bureau
    against which you can test clients.</li>
  <li><a href="http://www.w3.org/pub/WWW/PICS/extensions/">Protocol
    extensions.</a> These are extensions that people have defined using the
    extension mechanisms provided in the technical specifications.</li>
  <li><a href="http://www1.raleigh.ibm.com/pics/hints.html">Hints to
    implementors</a></li>
  <li>Various tools and free technical advice available from the <a
    href="http://www.si.umich.edu/~presnick/PICS-incubator/">PICS Application
    Incubator</a> project at the University of Michigan School of
  Information.</li>
</ul>

<h3>Resources for Labeling Service Developers</h3>

<p>To start a new labeling service, you will need to take the following
steps:</p>
<ol>
  <li>Decide who will assign labels.
    <ul>
      <li>Web site operators who self-label <i>and/or</i></li>
      <li>A panel of raters that you recruit <i>and/or</i></li>
      <li>A computer program that analyzes the contents of materials and
        assigns labels</li>
    </ul>
  </li>
  <li>Decide the labeling vocabulary and criteria</li>
  <li>Express the labeling vocabulary and criteria according to the format
    specified in the <a
    href="http://www.w3.org/TR/REC-PICS-services">technical specification</a>.
    You can create this file from scratch, or you can fill out web forms at
    the <a href="http://www.si.umich.edu/~presnick/PICS-incubator/">PICS
    Application Incubator</a> and the file will be created for you.</li>
  <li>Create the labels</li>
  <li>Arrange for distribution of your labels
    <ul>
      <li>Give your labels to someone else who is running a PICS label bureau
        <i>and/or</i></li>
      <li>Run your own PICS label bureau <i>and/or</i></li>
      <li>Convince web site operators to distribute the labels for their own
        pages, either by putting them into HTML META tags or sending them
        along with web pages.</li>
    </ul>
  </li>
</ol>

<p>The <a href="http://www.si.umich.edu/~presnick/PICS-incubator/">PICS
Application Incubator</a> project at the University of Michigan School of
Information will provide a limited amount of free technical consulting to
organizations that are considering establishing new labeling services.</p>

<h2><a name="Products"></a>Lists of PICS-compatible products and
services.</h2>

<p><b><a href="http://www.research.att.com/~lorrie/pubs/tech4kids/">Technology
Inventory</a></b> [broken link as of July 2005].
Lorrie Cranor and Paul Resnick. This inventory was first
distributed at the December 1997 Internet On-line summit: Focus on Children.
The on-line version was updated until the summer of 1999. It also lists some
products and services  that are not PICS-compatible.</p>

<p>The following resource lists are being maintained by members of the PICS
developers' community. Contact the maintainer of each individual list with
additional links. The maintainers have all agreed to be fast and fair in
maintaining these lists (please send any unresolved complaints to
pics-ask@w3.org).</p>
<ul>
  <li><a href="http://www.microsys.com/pics/">Client software</a>
    [broken link as of July 2005] that reads
    PICS labels.</li>
  <li><a href="http://www1.raleigh.ibm.com/pics/servers.html">HTTP servers</a>
    that distribute labels along with documents.</li>
  <li><a href="http://www.n2h2.com/pics/proxy_servers.html">Proxy servers</a>
    [broken link as of July 2005]
    that perform filtering based on PICSRules.</li>
  <li><a href="bureaus.htm">Label bureaus</a>: HTTP servers that distribute
    third-party PICS labels through the PICS label bureau query protocol.</li>
  <li><a href="raters.htm">Rating services</a></li>
  <li><a href="http://www.xav.com/scripts/search/">Search engine</a> that can use PICS labels in its selection criteria</li>
  <li><a href="http://www.getnetwise.org">more information</a> "for families
    and caregivers" from <a
    href="http://www.getnetwise.org/supporters.shtml">GetNetWise</a>
    [broken link as of July 2005]</li>
</ul>

<h2><a name="Innovations"></a>Innovative Uses of PICS Labels</h2>

<p>The most common uses of PICS labels have been in filtering products that
block access to certain materials based on labels associated with those
materials. The <a
href="http://www.research.att.com/~lorrie/pubs/tech4kids/">technology
inventory</a>, however, identifies a range of other actions that can be taken
based on labels: suggest, search, inform, monitor/log, and warn.</p>
<ul>
  <li>Inform: <a href="http://www.medcertain.org">med-PICS</a>; a collaboration
    for critical appraisal of medical information on the Internet</li>
  <li>Search: <a href="http://www.netshepherd.com">Net Shepherd and Alta Vista
    offer filtered Internet search</a>
    [broken link as of July 2005]</li>
  <li>Inform: <a href="http://www.alexa.com">Alexa Internet</a> displays PICS
    labels visually, but does not block access based on those labels.</li>
  <li>Inform: The Test-a-URL feature created by the <a
    href="http://www.si.umich.edu/~presnick/PICS-incubator/">PICS Application
    Incubator</a> lets you see what labels have been assigned to any URL by
    several different rating services. (A <a
    href="http://cgi.pathfinder.com/netly/spoofcentral/censored/">similar
    test-a-URL feature</a> is available for other, non PICS-based
  services.)</li>
</ul>

<h2><a name="Authors"></a>Hints for Web Site Authors Who Want to
Self-Label</h2>

<p>Many authors and web site operators offer materials that they realize will
not be appropriate for all audiences. We encourage them to label their
materials to make it easier for filtering software to block access. As an
added inducement to labeling, we note that some future applications may use
labels for searching as well as filtering. Thus, labeling your site will make
it easier both for some audiences to avoid your site or documents and for
others to find you.</p>

<p>PICS is able to remain value-neutral by refusing to endorse any particular
labeling vocabulary. As a web site operator, you will not have that luxury.
You'll want to adopt one or more of the rating vocabularies that other sites
are using. You may want to use one of the <a
href="raters.htm#self">self-rating vocabularies</a>.</p>

<p>Once you have created a label, you will need to distribute it along with
your document(s). PICS has defined several ways to do that. The recommended
method, if your HTTP server allows it, is to insert an extra header in the
HTTP header stream that precedes the contents of documents that are sent to
web browsers. The correct format, as documented in the specifications, is to
include the two headers, Protocol and PICS-Label:</p>

<div class="header-example">
<p>HTTP/1.0 200 OK <br>
Date: Thu, 30 Jun 1995 17:51:47 GMT <br>
Last-modified: Thursday, 29-Jun-95 17:51:47 GMT <br>
Protocol: {PICS-1.1 {headers PICS-Label}} <br>
PICS-Label: <br>
 (PICS-1.1 "http://www.gcf.org/v2.5" labels <br>
  on "1994.11.05T08:15-0500" <br>
  exp "1995.12.31T23:59-0000" <br>
  for "http://www.greatdocs.com/foo.html" <br>
  by "George Sanderson, Jr." <br>
  ratings (suds 0.5 density 0 color/hue 1)) <br>
Content-type: text/html</p>

<p>...contents of foo.html...</p>
</div>

<p>The server can send these headers even if the browser has not specifically
request them.</p>

<p>The next best method is to run a label bureau at a specific location on
your server, as specified in a <a href="defaults.html">supplement</a> to the
PICS specs, distributing labels only for documents on your server.</p>

<p>If neither of these methods is not available to you, a simpler but more
limited method is to embed labels in HTML documents using a META tag. With
this method, you will be able to send labels only with HTML documents, not
with images, video, or anything else. You may also find it cumbersome to
insert the labels into every HTML document. Some browsers, notably Microsoft's
Internet Explorer versions 3 and 4, will download the root document for your
web server and look for a generic label there. For example, if no labels were
embedded in the HTML for this web page (they are), Internet Explorer would
look for a generic label embedded in the page at http://www.w3.org/ (generic
labels can be found there). Be sure to read the <a
href="defaults.html">supplement </a>for information on when specific labels
override generic labels and when they don't.</p>

<p>The following is a an example of the right way to embed a PICS label in an
HTML document:</p>

<h3>RIGHT!</h3>
<pre>&lt;head&gt;

 &lt;META http-equiv="PICS-Label" content='

 (PICS-1.1 "http://www.gcf.org/v2.5"

    labels on "1994.11.05T08:15-0500"

           until "1995.12.31T23:59-0000"

           for "http://w3.org/PICS/Overview.html"

    ratings (suds 0.5 density 0 color/hue 1))

 '&gt;

 &lt;/head&gt;

 ...contents of document here...</pre>

<p>The following is incorrect, because the label is in the body of the
document rather than in the HTML header (delimited by &lt;head&gt; and
&lt;/head&gt;).</p>

<h3>WRONG!</h3>
<pre>&lt;head&gt;

 &lt;/head&gt;

 &lt;META http-equiv="PICS-Label" content='

 (PICS-1.1 "http://www.gcf.org/v2.5"

    labels on "1994.11.05T08:15-0500"

           until "1995.12.31T23:59-0000"

           for "http://w3.org/PICS/Overview.html"

    ratings (suds 0.5 density 0 color/hue 1))</pre>
<pre> '&gt;

 ...contents of document here...</pre>

<p>It is OK to include more than one META tag in a single HTML document, so
you can provide labels according to several services. There also is a way to
combine several labels into a single label list. See the <a
href="#Specs">technical specifications</a> for details.</p>

<h2><a name="RDF">RDF</a></h2>

<p>Separate W3C working groups are developing a new label format, called RDF;
the Resource Description Framework, based on XML. <a
href="/TR/REC-rdf-syntax">RDF labels</a> will be able to express everything
that PICS labels can express, but will also permit string and structured
values, and some other nifty features. The latest information on this
available at <a href="http://www.w3.org/RDF">http://www.w3.org/RDF.</a></p>

<h2><a name="FAQ"></a>Frequently Asked Questions</h2>

<p>A separate <a href="http://www.w3.org/2000/03/PICS-FAQ">PICS FAQ</a>
document is available, offering answers to a number of common questions about
PICS. In addition a <a href="PICS-FAQ-980126.html">separate FAQ</a> addresses
intellectual freedom implications of PICS.</p>
<hr>
<address>
  Comments to <a href="mailto:PICS-ask@w3.org">PICS-ask@w3.org</a>.
</address>
<address>
  <a href="../Help/Webmaster.html">Webmaster</a>
</address>
<address>
  $Date: 2009/11/20 13:45:12 $ by $Author: phila $
</address>

<p class="copyright"><a rel="Copyright"
href="/Consortium/Legal/ipr-notice#Copyright">Copyright</a> &#xa9; 1997-2003
<a href="/"><acronym
title="World Wide Web Consortium">W3C</acronym></a><sup>&#xae;</sup> (<a
href="http://www.lcs.mit.edu/"><acronym
title="Massachusetts Institute of Technology">MIT</acronym></a>, <a
href="http://www.ercim.org/"><acronym
title="European Research Consortium for Informatics and
Mathematics">ERCIM</acronym></a>, <a
href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved.

W3C <a
href="/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a
href="/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>, <a
rel="Copyright" href="/Consortium/Legal/copyright-documents">document
use</a>
and <a rel="Copyright" href="/Consortium/Legal/copyright-software">software
licensing</a> rules apply. Your interactions with this site are in
accordance
with our <a href="/Consortium/Legal/privacy-statement#Public">public</a> and
<a href="/Consortium/Legal/privacy-statement#Members">Member</a> privacy
statements.
</p>

</body>
</html>