reg.txt

Example structure:
HKEY_LOCAL_MACHINE
   %ApplicationCapabilityPath%
      ApplicationDescription
      ApplicationName
      Hidden
      FileAssociations
         .file-extension1
         .file-extension2
         ...
         .file-extensionX
      MIMEAssociations
         MIME
      Startmenu
         StartmenuInternet
         Mail
      UrlAssociations
         url-scheme
   SOFTWARE
      RegisteredApplications
         Unique Application Name = %ApplicationCapabilityPath%


Example of implementation:
HKEY_LOCAL_MACHINE
   SOFTWARE
      Contoso
         WebBrowser
            Capabilities
               ApplicationDescription = This award-winning Contoso browser is better than ever. Search the Internet and find exactly what you want in just seconds. Use integrated tabs and new phishing detectors to enhance your Internet experience.
               FileAssociations
                  .htm = ContosoHTML
                  .html = ContosoHTML
                  .shtml = ContosoHTML
                  .xht = ContosoHTML
                  .xhtml = ContosoHTML
               Startmenu
                  StartmenuInternet = Contoso.exe
               UrlAssociations
                  http = Contoso.Url.Http
                  https = Contoso.Url.Https
                  ftp = Contoso.Url.ftp
   SOFTWARE
      RegisteredApplications
         Contoso.WebBrowser.1.06 = SOFTWARE\Contoso\WebBrowser\Capabilities