title: Are line breaks in XML attribute values allowed?
body: <p>I realise that it's not elegant or desired, but is it allowed (in well-formed XML) for an attribute value in an XML element to span multiple lines?</p>
  
  <p>e.g.</p>
  
  <pre><code>&lt;some-xml-element value="this value goes over....
  multiple lines!" /&gt;
  </code></pre>
  
  <p>Yeah I realise there's better ways of writing that. I would personally write it like:</p>
  
  <pre><code>&lt;some-xml-element&gt;
  &lt;value&gt;this value goes over...
  multiple lines!&lt;/value&gt;
  &lt;/some-xml-element&gt;
  </code></pre>
  
  <p>or:</p>
  
  <pre><code>&lt;some-xml-element value="this value goes over....&amp;#13;&amp;#10;" /&gt;
  </code></pre>
  
  <p>But we have our own XML parser and I'd like to know whether the first example is allowed in well-formed XML.</p>