written for v2.4.x and
    earlier.  See CHANGES and the documentation for the
    <a href="resources/mimefilters.html">MIMEFILTERS</a> resource
    for the API.
    </p>
    <p>If you use custom style filters written for v2.4.x, or earlier,
    you will need to update them for them to work properly under
    v2.5, and later.
    </p>

<h3><a name="v2.1.x-dbedit">UPGRADING FROM v2.1.x OR EARLIER: Database Format Change</a></h3>
    
    <p>If you have archives created with v2.1.x, or earlier, the
    format