Hiding placemarks in KML used to center and zoom a map - google-maps

Question

I have a embedded map on my site in which I display various location based on the user's search results. In some cases we do not have location data and instead display a screen overlay indicating this. I additionally set a couple of placemarks to force the map to zoom and center on a specific region (the default if there is no location data being the full zoom out, which is kind of ugly).
My problem is I want to hide these placemarks, as otherwise they appear to indicate there are locations available and none of the following has worked:
the visibility flag on elements seems to only be supported in google earth
a custom transparent png specified as the Placemark Icon href does not load, and I get the default blue pin.
I tried creating a region on the folder which encompasses the placemarks and setting a LOD which should disable it, but this appears to not do anything at all (KML below).
I believe I am missing a simple way to accomplish this, but a nudge would be helpful. Here is the KML using regions:
<?xml version="1.0" encoding="utf-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document>
<ScreenOverlay>
<Icon>
<href>URL/mapDisclaimer.png</href>
</Icon>
<overlayXY x="0.5" xunits="fraction" y="0.5" yunits="fraction" />
<screenXY x="0.5" xunits="fraction" y="0.5" yunits="fraction" />
<size x="0" xunits="pixels" y="0" yunits="pixels" />
</ScreenOverlay>
<Folder>
<name>PlaceHolderFolder</name>
<Style id="placeholderStyle">
<IconStyle>
<Icon>
<href>URL/transparentBlock.png</href>
</Icon>
</IconStyle>
</Style>
<Region>
<LatLonAltBox>
<north>79</north>
<south>59</south>
<east>-102</east>
<west>-137</west>
</LatLonAltBox>
<Lod>
<maxLodPixels>20</maxLodPixels>
</Lod>
</Region>
<Placemark>
<styleUrl>#placeholderStyle</styleUrl>
<Point>
<coordinates>-136.582031,69.16256</coordinates>
</Point>
</Placemark>
<Placemark>
<styleUrl>#placeholderStyle</styleUrl>
<Point>
<coordinates>-110.566406,78.560486</coordinates>
</Point>
</Placemark>
<Placemark>
<styleUrl>#placeholderStyle</styleUrl>
<Point>
<coordinates>-102.128906,59.977005</coordinates>
</Point>
</Placemark>
</Folder>
</Document>
</kml>

Answer 1

The transparent PNG should work, but you must move the <Style/>-element out of <Folder/> and make it a child of <Document/>