<settings.flex.usernameMinimumLengthActive>
    <TCEforms>
        <label>LLL:EXT:rm_registration/Resources/Private/Language/locallang_db.xlf:extension_flexform.usernameMinimumLengthActive</label>
        <config>
            <type>check</type>
            <items type="array">
                <numIndex index="1" type="array">
                    <numIndex index="0">LLL:EXT:lang/Resources/Private/Language/locallang_core.xlf:labels.enabled</numIndex>
                    <numIndex index="1">1</numIndex>
                </numIndex>
            </items>
        </config>
    </TCEforms>
</settings.flex.usernameMinimumLengthActive>