Share a placemark description - kml

Question

I've created a geologic units map. Each geologic unit is composed of multiple placemark polygons. I currently have the same geologic unit description repeated in each placemark composing the geologic unit in order to get the functionality I want (click on the polygon and get a description).
Is there a way to include the geologic unit description once in the KML file and use it on multiple polygons?
Here's an example of what I currently have:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<name>Geologic Units</name>
<open>1</open>
<Style id="style22">
<LineStyle>
<color>40000000</color>
</LineStyle>
<PolyStyle>
<color>996ca66c</color>
</PolyStyle>
</Style>
<Folder>
<name>Cokeville Formation (Lower Cretaceous)</name>
<Placemark>
<name>Cokeville Formation</name>
<description><![CDATA[<p>UNITSYMBOL: Kc</p><p>UNITNAME: Cokeville Formation</p><p>AGE: Lower Cretaceous</p><p>Description: Interbedded dark-gray, carbonaceous, shaly mudstone and siltstone, tan-weathering sandstone, and gray to tan limestone and coquina containing gastropod (Pyrgulifera) and pelecypod fauna. hickness about 650 m. Mapped only along southeastern edge of map area</p>]]></description>
<styleUrl>#style22</styleUrl>
<Polygon>
<outerBoundaryIs>
<LinearRing>
<tessellate>1</tessellate>
<coordinates>
-111.001621832,41.6548237803,0 -111.000744207,41.6560784513,0 -111.00074419,41.6548059965,0 -111.001123716,41.6547959594,0 -111.001621832,41.6548237803,0
</coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
</Placemark>
<Placemark>
<name>Cokeville Formation</name>
<description><![CDATA[<p>UNITSYMBOL: Kc</p><p>UNITNAME: Cokeville Formation</p><p>AGE: Lower Cretaceous</p><p>Description: Interbedded dark-gray, carbonaceous, shaly mudstone and siltstone, tan-weathering sandstone, and gray to tan limestone and coquina containing gastropod (Pyrgulifera) and pelecypod fauna. hickness about 650 m. Mapped only along southeastern edge of map area</p>]]></description>
<styleUrl>#style22</styleUrl>
<Polygon>
<outerBoundaryIs>
<LinearRing>
<tessellate>1</tessellate>
<coordinates>
-111.010074925,41.6544088836,0 -111.009817106,41.6540759648,0 -111.009537791,41.6538429717,0 -111.009365835,41.6535267043,0 -111.009150955,41.6532271007,0 -111.008914576,41.653010725,0 -111.008549317,41.6527943596,0 -111.00861367,41.6521452029,0 -111.008506241,41.6516790986,0 -111.008466501,41.6515573391,0 -111.009350608,41.6513600036,0 -111.01081154,41.6510769006,0 -111.011498939,41.6510102244,0 -111.011406521,41.6517787096,0 -111.011019912,41.6519285808,0 -111.010590221,41.6523613799,0 -111.01028951,41.6528275229,0 -111.010246703,41.6535765651,0 -111.010160817,41.6540093659,0 -111.010074925,41.6544088836,0
</coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
</Placemark>
</Folder>
</Document>
</kml>

Answer 1

I figured out how to do it with BalloonStyle Text. Is this the only way or is there another/better way?
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<name>Geologic Units</name>
<open>1</open>
<Style id="style22">
<BalloonStyle>
<text><![CDATA[<p>UNITSYMBOL: Kc</p><p>UNITNAME: Cokeville Formation</p><p>AGE: Lower Cretaceous</p><p>Description: Interbedded dark-gray, carbonaceous, shaly mudstone and siltstone, tan-weathering sandstone, and gray to tan limestone and coquina containing gastropod (Pyrgulifera) and pelecypod fauna. hickness about 650 m. Mapped only along southeastern edge of map area</p>]]></text>
</BalloonStyle>
<LineStyle>
<color>40000000</color>
</LineStyle>
<PolyStyle>
<color>996ca66c</color>
</PolyStyle>
</Style>
<Folder>
<name>Cokeville Formation (Lower Cretaceous)</name>
<Placemark>
<name>Cokeville Formation</name>
<styleUrl>#style22</styleUrl>
<Polygon>
<outerBoundaryIs>
<LinearRing>
<tessellate>1</tessellate>
<coordinates>
-111.001621832,41.6548237803,0 -111.000744207,41.6560784513,0 -111.00074419,41.6548059965,0 -111.001123716,41.6547959594,0 -111.001621832,41.6548237803,0
</coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
</Placemark>
<Placemark>
<name>Cokeville Formation</name>
<styleUrl>#style22</styleUrl>
<Polygon>
<outerBoundaryIs>
<LinearRing>
<tessellate>1</tessellate>
<coordinates>
-111.010074925,41.6544088836,0 -111.009817106,41.6540759648,0 -111.009537791,41.6538429717,0 -111.009365835,41.6535267043,0 -111.009150955,41.6532271007,0 -111.008914576,41.653010725,0 -111.008549317,41.6527943596,0 -111.00861367,41.6521452029,0 -111.008506241,41.6516790986,0 -111.008466501,41.6515573391,0 -111.009350608,41.6513600036,0 -111.01081154,41.6510769006,0 -111.011498939,41.6510102244,0 -111.011406521,41.6517787096,0 -111.011019912,41.6519285808,0 -111.010590221,41.6523613799,0 -111.01028951,41.6528275229,0 -111.010246703,41.6535765651,0 -111.010160817,41.6540093659,0 -111.010074925,41.6544088836,0
</coordinates>
</LinearRing>
</outerBoundaryIs>
</Polygon>
</Placemark>
</Folder>
</Document>
</kml>

Answer 2

For your use-case, a shared Style with a BalloonStyle containing a balloon template is probably the best way to go. You can take this a step further and include placeholder variables in the BalloonStyle template, which get replaced by contents of the ExtendedData section in each Placemark. That said, another way it can be done is to combine the relevant polygons into one Placemark, using a MultiGeometry, but only if you want the combined polygons to act as one on the map.