    added. This is a reference to the
        <span class="code">weewx</span> engine.</p>
    
    <p>This change will affect only those who have written their own device
        driver. </p>
    
    <h2>From V2.1 or earlier</h2>
    
    <p>Version 2.2 introduces a schema, found in <span class="code">
        bin/user/schemas.py</span>, for the stats database. This schema is used
        only when initially creating the database. If you have a specialized
        stats database, that is, one that saves ty