Copy the following text and paste it into a text file, then save that file as "contents.rdf":
<?xml version="1.0"?>
<RDF:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:chrome="http://www.mozilla.org/rdf/chrome#">
<!-- List all the skins being supplied by this theme -->
<RDF:Seq about="urn:mozilla:skin:root">
<RDF:li resource="urn:mozilla:skin:mySkin/1.0" />
</RDF:Seq>
<RDF:Description about="urn:mozilla:skin:mySkin/1.0"
chrome:displayName="My Skin"
chrome:accessKey="M"
chrome:author="Me"
chrome:description="This is my custom skin for mozilla"
chrome:name="mySkin/1.0"
chrome:image="preview.png">
<chrome:packages>
<RDF:Seq about="urn:mozilla:skin:mySkin/1.0:packages">
<RDF:li resource="urn:mozilla:skin:mySkin/1.0:communicator"/>
<RDF:li resource="urn:mozilla:skin:mySkin/1.0:editor"/>
<RDF:li resource="urn:mozilla:skin:mySkin/1.0:global"/>
<RDF:li resource="urn:mozilla:skin:mySkin/1.0:messenger"/>
<RDF:li resource="urn:mozilla:skin:mySkin/1.0:navigator"/>
</RDF:Seq>
</chrome:packages>
</RDF:Description>
<!-- Version Information. State that we work only with major version 1 of this
package. -->
<RDF:Description chrome:skinVersion="1.0" about="urn:mozilla:skin:mySkin/1.0:communicator"/>
<RDF:Description chrome:skinVersion="1.0" about="urn:mozilla:skin:mySkin/1.0:editor"/>
<RDF:Description chrome:skinVersion="1.0" about="urn:mozilla:skin:mySkin/1.0:global"/>
<RDF:Description chrome:skinVersion="1.0" about="urn:mozilla:skin:mySkin/1.0:messenger"/>
<RDF:Description chrome:skinVersion="1.0" about="urn:mozilla:skin:mySkin/1.0:navigator"/>
</RDF:RDF>