<svg xmlns="http://www.w3.org/2000/svg">
    <metadata>
        <sfw>
            <slices></slices>
            <sliceSourceBounds height="67.3" width="85.9" y="-40.8" x="-42.5" bottomLeftOrigin="true"></sliceSourceBounds>
        </sfw>
    </metadata>
</svg>

@@@

<svg xmlns="http://www.w3.org/2000/svg">
    <metadata>
        <sfw>
            <slices/>
            <sliceSourceBounds height="67.3" width="85.9" y="-40.8" x="-42.5" bottomLeftOrigin="true"/>
        </sfw>
    </metadata>
</svg>

Add some permitted and not permitted elements to the unknown element test
Add some permitted and not permitted elements to the unknown element test
