We're pleased to announce we're beginning work on an IETF Internet-Draft for the Do Not Track header. We look forward to incorporating broad feedback.
In anticipation of the first version of the Internet-Draft, we're making a few minor updates to the header. The reference implementations at DoNotTrack.Us will be revised shortly.
Since Do Not Track is entering a standardization process, convention dictates dropping the prefix "X-".
In keeping with header naming best practices, and to conserve network resources, we're shortening the name.
Adding a "0" Value
There's an important policy distinction between users who consent to third-party tracking and users who haven't expressed a preference. To clarify this difference, the header now has three states:
"DNT: 1" - The user opts out of third-party tracking.
"DNT: 0" - The user consents to third-party tracking.
[No Header] - The user has not expressed a preference about third-party tracking.