Error using :after

Walt Farrell <[email protected]> Tue, 23 Jun 2015 18:17:06 -0400
Newsgroups	gmane.org.w3c.validator.css
Message-ID	<[email protected]>
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Suddenly the W3C CSS validator is complaining about a statement that I 
do not believe it has complained about before.

Statement:
    .pageno:after { color: silver; content: attr(title); }

Error message:
18 	.pageno:after 	Value Error : content 
<http://www.w3.org/TR/2011/REC-CSS2-20110607/generate.html#propdef-content> 
Parse Error attr(title)


I'm validating as CSS 2.1. Is that statement really invalid for some 
reason I don't understand, or has a recent change to the validator 
introduced this behavior in error?

Thanks,
Walt


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<html>
  <head>

    <meta http-equiv="content-type" content="text/html; charset=utf-8">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    Suddenly the W3C CSS validator is complaining about a statement that
    I do not believe it has complained about before.<br>
    <br>
    Statement:<br>
       .pageno:after { color: silver; content: attr(title); }<br>
    <br>
    Error message:<br>
    <table>
      <tbody>
        <tr class="error">
          <td class="linenumber" title="Line 18">18</td>
          <td class="codeContext"> .pageno:after </td>
          <td class="parse-error"> Value Error : <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/generate.html#propdef-content">content</a>
            Parse Error <span class="unrecognized"> attr(title) </span></td>
        </tr>
      </tbody>
    </table>
    <br>
    I'm validating as CSS 2.1. Is that statement really invalid for some
    reason I don't understand, or has a recent change to the validator
    introduced this behavior in error?<br>
    <br>
    Thanks,<br>
    Walt<br>
    <br>
  </body>
</html>

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