small elementHTMLElement.The small element represents side
  comments such as small print.
Small print typically features disclaimers, caveats, legal restrictions, or copyrights. Small print is also sometimes used for attribution, or for satisfying licensing requirements.
The small element does not
  "de-emphasize" or lower the importance of text emphasized by the
  em element or marked as important with the
  strong element. To mark text as not emphasized or
  important, simply do not mark it up with the em or
  strong elements respectively.
The small element should not be used for extended
  spans of text, such as multiple paragraphs, lists, or sections of
  text. It is only intended for short runs of text. The text of a page
  listing terms of use, for instance, would not be a suitable
  candidate for the small element: in such a case, the
  text is not a side comment, it is the main content of the page.
In this example, the small element is used to
   indicate that value-added tax is not included in a price of a hotel
   room:
<dl> <dt>Single room <dd>199 € <small>breakfast included, VAT not included</small> <dt>Double room <dd>239 € <small>breakfast included, VAT not included</small> </dl>
In this second example, the small element is used
   for a side comment in an article.
<p>Example Corp today announced record profits for the second quarter <small>(Full Disclosure: Foo News is a subsidiary of Example Corp)</small>, leading to speculation about a third quarter merger with Demo Group.</p>
This is distinct from a sidebar, which might be multiple paragraphs long and is removed from the main flow of text. In the following example, we see a sidebar from the same article. This sidebar also has small print, indicating the source of the information in the sidebar.
<aside> <h1>Example Corp</h1> <p>This company mostly creates small software and Web sites.</p> <p>The Example Corp company mission is "To provide entertainment and news on a sample basis".</p> <p><small>Information obtained from <a href="http://example.com/about.html">example.com</a> home page.</small></p> </aside>
In this last example, the small element is marked
   as being important small print.
<p><strong><small>Continued use of this service will result in a kiss.</small></strong></p>