Nope, I'll set an example:
XML code:
<!-- Change to FigureElement for testing -->
<Element xsi:type="PlaceHolderElement" Id="Nothing">
<Position Left="103" Top="20" Width="500" Height="350">
<Anchor Horizontal="LeftRightFixed" Vertical="TopBottomFixed"/>
</Position>
<Figure>
<Rectangle/>
</Figure>
<Fill>
<PlainColor>
<BaseColor>
<Transparency>200</Transparency>
</BaseColor>
</PlainColor>
</Fill>
</Element>
The code above is taken
directly from one of my interface files (well, I removed a bunch of tabs...). As you can see, I've added a bunch of XML elements that are used for FigureElements, but not for PlaceHolderElements. It'd be useful if one could add the comment at the top of the code so they won't remove the additional XML elements, in case they forget why the "useless" data is in the PlaceHolderElement.