It's important to note that the Do-Not-Stab header has been deprecated because one browser engine switched it on by default and requiring users to opt into stabbing hurt the bottom line of the stabbing industry, so it's no longer respected. Luckily someone came up with General Assault Control, a non-standard alternative, which also only has one value, so you can set Sec-GAC to 1 to request websites not to assault you. By design, this header cannot be extended, so it cannot be used to distinguish brutal stabbings from a comedic pie to the face in the future.

Because of legal requirements, the General Assault Control header may not be enabled by default, as American states like Colorado require explicit opt-out (rather than explicit opt-in). This protects Colorado's thriving stabbing and shooting industry as most users will never want to opt into being stabbed.

Despite the feature being forced to be disabled by default, the organisation behind the spec is pushing hard for customers to download fringe browsers that implement the feature (though you may need about:config to enable it). Because of the small user base, the request not to be assaulted can be used by websites not willing to follow the standard to make their stabbings and shootings more precise. End users can request a JSON file from the web server containing the supposed support for the GAC header, but requesting this URL may be used to kick the user in the teeth by non compliant servers.