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Clear-Site-Data

Security Policy IANA permanent reached by regulation

Erasure carried out at the client boundary. Nobody in the catalog declares it.

Clear-Site-Data instructs the browser to discard cookies, storage and caches for the origin. It exists for logout and for account deletion, and it is the only mechanism HTTP offers for reaching data that has already left your servers.

Under GDPR, erasure is an obligation about personal data wherever it rests, and data cached in a browser is data. Nothing in the regulation names this header — the connection is evidentiary, not mandated — but if you have ever tried to answer “we deleted everything” honestly, this is part of the answer.

No provider in the catalog declares it.

The registry

Listed in the IANA HTTP Field Name Registry as a permanent entry. Defined in Clear Site Data.

In the catalog

Registered with IANA and declared by not one of the 26,641 providers in the API Evangelist catalog. A registered field with no observed use is still part of the vocabulary — it just is not part of the practice.

Reached by regulation

No law names this header. It is evidentiary — the deployed control for an obligation that regulation does impose. It is observable at the edge: an unauthenticated request is enough to see whether a provider sends it.

Using it

Send it on logout and on account deletion. "cookies" alone is the safe starting point; "*" will also clear caches and can be surprising. It only applies to the origin sending it, so a logout that spans several origins needs the header from each of them.

Reached by these regulations

Catalogued at regulations.apievangelist.com, with the basis of each connection recorded rather than implied.

Governed by these rules

Machine-enforceable governance rules from rules.apievangelist.com that apply to this header when it appears in an OpenAPI.

OpenAPI Components Headers Error error

Utilizing the headers object in the centralized OpenAPI components library helps make headers reusable across API requests and responses

Guidance: Rate Limits →
OpenAPI Components Headers Info info

Utilizing the headers object in the centralized OpenAPI components library helps make headers reusable across API requests and responses

Guidance: Rate Limits →
OpenAPI Headers Hyphenated Pascal Case error

HTTP headers should follow Hyphenated-Pascal-Case naming convention for consistency and readability, such as Content-Type, X-Request-Id, or Accept-Language.

Guidance: Naming →