~ $ cat /usr/share/polkit-1/actions/org.x.xf86-video-intel.backlight-helper.policy 
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policyconfig PUBLIC
 "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
<policyconfig>
  <vendor>The X.Org project</vendor>
  <vendor_url>https://01.org/linuxgraphics/community/xf86-video-intel</vendor_url>
  <icon_name>brightness</icon_name>
  <action id="org.x.xf86-video-intel.backlight-helper">
    <description>Modify lcd panel brightness</description>
    <message>Authentication is required to modify the lcd panel brightness</message>
    <defaults>
      <allow_any>no</allow_any>
      <allow_inactive>no</allow_inactive>
      <allow_active>yes</allow_active>
    </defaults>
    <annotate key="org.freedesktop.policykit.exec.path">/usr/libexec/xf86-video-intel-backlight-helper</annotate>
  </action>
</policyconfig>