What is a do-not-track (DNT) signal?
Do Not Track is a web browser setting to opt-out of the tracking of analytics services, advertising networks and other privacy threats.
How does it work?
When you browse on the Internet, multiple requests and responses happen between your browser and the website you are visiting. These are called HTTP 2 headers, and Do Not Track signals are part of them. They have three different values:
1: The user does not wish to be tracked
0: The user consents to tracking
No header field: The user didn’t set a preference
When the website recognises the DNT header, it may stop third-party tracking.
Are websites legally compelled to respect these signals?
Currently, there aren’t any common laws regulating responses to do-not-track. Therefore turning on this setting isn’t a guarantee at all: most websites simply ignore the request and track visitors anyway. However, websites’ Privacy Policies usually have to explain how they interact with the signal.
https://www.eff.org/issues/do-not-track - How it works and purposes
https://en.wikipedia.org/wiki/Do_Not_Track - General Information
https://www.privacypolicies.com/blog/privacy-policy-dnt-do-not-track/ - Privacy Policies Legislation