contentstrictoriginwhencrossorigin

ContentStrictOriginWhenCrossOrigin is not an official HTTP header or policy directive. The term appears to be a misnom or blend of concepts used to discuss cross-origin requests and privacy, but there is no standard standard named exactly this. The closest official references involve the Referrer-Policy and, separately, the Content Security Policy.

The most relevant standard is the Referrer-Policy with the value strict-origin-when-cross-origin. This policy governs how much of the referring URL is sent with requests to other origins. Under this policy, when a navigation remains within the same origin, the full URL is sent as the Referer. When navigating to a different origin, only the origin (scheme, host, and port) is sent. If the navigation would downgrade security from HTTPS to HTTP, the Referer may be omitted entirely.

Content-Security-Policy is a separate mechanism that controls which resources a page is allowed to load or execute. It does not define any directive named strict-origin-when-cross-origin. CSP uses directives such as default-src, script-src, and img-src to constrain sources of content and is primarily aimed at reducing the risk of cross-site scripting and data injection, rather than controlling Referer headers.

Practical guidance: if the goal is to control cross-origin referrer information, configure a clear Referrer-Policy header (for example, Referrer-Policy: strict-origin-when-cross-origin) or equivalent meta tag. If CSP is also needed, implement it separately with appropriate source directives. Be aware that some older browsers may not support the chosen policy, and testing across platforms is advisable.