Maybe this will be allowed by Google+ eventually

Sidewiki syntax

<p>Sidewiki supported the following HTML tags within entries:</p><br>
<p>Font formatting</p>
<p>
<ul>
<li>b	 <code>     <b>Bold text</b></code>	</li>
<li>em	      <code<em>Emphasize your text</em></code></li>
<li>i	      <code><i>Italicize your text</i></code></li>
<li>strike      <code><strike>Strike out text</strike></code></li>
<li>strong      <code><strong>strong font</strong></code></li>
<li>sup	   <code>Go <sup>superscript</sup></code></li>
<li>sub	  <code>The <sub>subscript</sub></code></li>
<li>u	      <code><u>Underline text</u></code>  </li>
</ul>
<br>
<p>Line-formatting  </p><br>
<p>p	      paragraph 1</p>
<p>br /	   This is a line. </p><br />
<br>
<p>Example	</p>
<p>This is a line.  </p>
<p>This is after the line break.</p>
<br>
<p>Hyperlinks  </p>
<p>a	     Link to <a href="http://www.google.com" alt="Google">www.google.com</a>	</p>
<p>Link to www.google.com and href, see above.  </p>
<br>
<p>Based on the br / tag, I'm guessing this is intended for HTML4/XHTML 1.0 but not HTML5.</p>
<p>
<a href="http://www.google.com/support/toolbar/bin/answer.py?hl=en&answer=163222&topic=24314">Information source</a> might return 404 error after 5 December 2011.
</p>
<blockquote>Page was last updated 09/27/2011</blockquote>