[recursive]

There's no need to notify the server that your user-agent is opting out of cookies. Cookies only work because your user agent remembers them. You can opt out of cookies today by turning off cookies in your user agent. As a bonus, this even works for shady servers that don't respect earnest requests.

[Semaphor]

All the tracking is far more involved than cookies though.

[deepstack]

Canvas GPU finger print, network analysis, you get tracked one way or another. Surf web with lynx or lynx2 only!

[recursive]

Yes. The comment I referred to specifically referred to cookies. Also, if you're being tracked by canvas fingerprinting and font enumeration, I doubt asking nicely will have any effect.