Which HTTP request headers are used by Piwik PRO?

When measuring activity with the tracking API for Piwik PRO, you can use the following HTTP headers:

• Host: The hostname of the HTTP request, the hostname of the Piwik PRO server
• Referrer: Used to track referrer information like website, search engine or social network.
• User-Agent: Used to detect the information about browsers, operating system, devices by the device-detector library.
• Cookie: Used for opted-out from tracking, or when the third0party cookies are used.
• Origin: Used when the cross-origin resource sharing is enabled.
• Accept-Language: Used to detect the user language.
• X-Forwarded-Proto, X-Forwarded-Host, X-Forwarded-For: Used when Piwik PRO is set up behind a proxy.
• DNT: Used to detect whether a visitor device is opted-out from tracking.