must be served using the text/html MIME type.
must be served using an XML MIME type, such as application/xhtml+xml or application/xml.
<li class="foo">Hello world</li>
<img src="foo" alt="bar" /><li class="foo">Hello world
<img src="foo" alt="bar"><LI CLASS="foo">Hello world</LI>
<IMG SRC="foo" ALT="bar"><li class=foo>Hello world</li>
<img src=foo alt=bar>—Parsing HTML documentsThis specification defines the parsing rules for HTML documents, whether they are syntactically correct or not.
<audio src="song.mp3" controls autobuffer>
<-- fallback content -->
</audio><video controls width="200" height="200">
<source type="video/ogg" src="movie.ogg">
<source type="video/mp4" src="movie.mp4">
<-- fallback content -->
</video><canvas width="200" height="200">
<-- fallback content -->
</canvas>