The MimeType key is used to indicate the MIME
      Types that an application knows how to handle. It is expected that
      for some applications this list could become long.  An application
      is expected to be able to reasonably open files of these types
      using the command listed in the Exec key.
    
      There should be no priority for MIME Types in this field, or any
      form of priority in the desktop file.  Priority for applications
      is handled external to the .desktop files.