xmlns:em="http://www.mozilla.org/2004/em-rdf#">
 <Description about="urn:mozilla:install-manifest">
   1.2.0.11
   ctviewer@camtrace.com
   2

   CamTrace Viewer
   Displays CamTrace video streams.
   
     <Description>
   <em:locale>fr-fr
   CamTrace Viewer  
   Affiche les flux video CamTrace.
     </Description>
   </em:localized>
   Camtrace S.A.S.
   http://www.camtrace.com/
   chrome://ctviewer/content/camtrace.png
   true

   
   
   <Description>
       <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}
       1.5
       4.*
   </Description>
   </em:targetApplication>
 </Description>

Hello, I got something really strange with my extension (which install a NPAPI plugin). I was used to update maxVersion property of the install.rdf every time a new major version of Firefox was released. Today, I wanted to give a try of installing the extension with a too lower maxVersion value. I was extremely surprised to see that Firefox accepted it. I was able to drop the maxVersion value down to "4.*" (lesser it says that Firefox is not compatible). I got it under Fedora and Windows. Here is my install.rdf: <?xml version="1.0"?> <RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#"> <Description about="urn:mozilla:install-manifest"> <em:version>1.2.0.11</em:version> <em:id>ctviewer@camtrace.com</em:id> <em:type>2</em:type> <em:name>CamTrace Viewer</em:name> <em:description>Displays CamTrace video streams.</em:description> <em:localized> <Description> <em:locale>fr-fr</em:locale> <em:name>CamTrace Viewer</em:name> <!-- Mandatory here --> <em:description>Affiche les flux video CamTrace.</em:description> </Description> </em:localized> <em:creator>Camtrace S.A.S.</em:creator> <em:homepageURL>http://www.camtrace.com/</em:homepageURL> <em:iconURL>chrome://ctviewer/content/camtrace.png</em:iconURL> <em:unpack>true</em:unpack> <!-- Firefox --> <em:targetApplication> <Description> <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id> <em:minVersion>1.5</em:minVersion> <em:maxVersion>4.*</em:maxVersion> </Description> </em:targetApplication> </Description> </RDF>