Just a <a href="/url/">URL</a>.

<a href="/url/" title="title">URL and title</a>.

<a href="/url/" title="title preceded by two spaces">URL and title</a>.

<a href="/url/" title="title preceded by a tab">URL and title</a>.

<a href="/url/" title="title has spaces afterward">URL and title</a>.

<a href="/url/has space">URL and title</a>.

<a href="/url/has space/" title="url has space and title">URL and title</a>.

<a href="">Empty</a>.