Add a header to the head of the response.

Attributes

Header nameDescription

Retry-After The Retry-After header field can be used with "502 Service Unavailable" to indicate how long the service is expected to be unavailable
WWW-Authenticate Must be included with a "401 Unauthorized" response, like this: <header name=WWW-Authenticate value="Basic; Realm=any">. The realm attribute is required for all access authentication schemes which issue a challenge. The realm value, in combination with the root URL of the server being accessed, will be presented to the user.
Location Must be included with a redirect of any kind, like this: <header name=Location value=URL>.
Content-LanguageThe language of the document
Content-EncodingThe encoding of the document
Content-TypeThe content type, usually text/html.
Derived-FromIndicates which document this document is derived from
ExpiresAfter the date indicated by this header, the document must be refetched from the server