title: Newlines and special characters in HTML attributes
body: <p>My questions are simple:</p>
  
  <p>Is the following valid? If it is, would it break in some browsers?</p>
  
  <pre><code>&lt;div data-text="Blah blah blah
  More blah
  And just a little extra blah to finish"&gt; ... &lt;/div&gt;
  </code></pre>
  
  <hr>
  
  <p>Which characters "must" be encoded in attribute values? I know <code>"</code> should be <code>&amp;quot;</code>, but are any others required to be encoded?</p>