showdown/test/functional/makehtml/cases/standard/anchors-allow-no-protocols.html

<p><a href="/uri">link</a></p>
<p><a href="http://example.com/">link</a></p>
<p><a href="http://example.com">link</a></p>
<p><a href="https://example.com">link</a></p>
<p><a href="https://example.com/">link</a></p>
<p><a href="example.com">link</a></p>
<p><a href="www.example.com">link</a></p>
<p><a href="file://example.com">link</a></p>
<p><a href="file://www.example.com">link</a></p>
<p><a href="example.jpg">link</a></p>
<p><a href="example.io">link</a></p>
<p><a href="http://baidu.com" title="百度">百度</a></p>