14.14 Content-Length

   The Content-Length entity-header field indicates the size of the
   message-body, in decimal number of octets, sent to the recipient or,
   in the case of the HEAD method, the size of the entity-body that
   would have been sent had the request been a GET.

          Content-Length    = "Content-Length" ":" 1*DIGIT

   An example is

          Content-Length: 3495

   Applications SHOULD use this field to indicate the size of the
   message-body to be transferred, regardless of the media type of the
   entity. It must be possible for the recipient to reliably determine
   the end of HTTP/1.1 requests containing an entity-body, e.g., because
   the request has a valid Content-Length field, uses Transfer-Encoding:
   chunked or a multipart body.

   Any Content-Length greater than or equal to zero is a valid value.
   Section 4.4 describes how to determine the length of a message-body
   if a Content-Length is not given.








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RFC 2068                        HTTP/1.1                    January 1997


     Note: The meaning of this field is significantly different from the
     corresponding definition in MIME, where it is an optional field
     used within the "message/external-body" content-type. In HTTP, it
     SHOULD be sent whenever the message's length can be determined
     prior to being transferred.

14.15 Content-Location

   The Content-Location entity-header field may be used to supply the
   resource location for the entity enclosed in the message. In the case
   where a resource has multiple entities associated with it, and those
   entities actually have separate locations by which they might be
   individually accessed, the server should provide a Content-Location
   for the particular variant which is returned. In addition, a server
   SHOULD provide a Content-Location for the resource corresponding to
   the response entity.

          Content-Location = "Content-Location" ":"
                            ( absoluteURI | relativeURI )

   If no Content-Base header field is present, the value of Content-
   Location also defines the base URL for the entity (see section
   14.11).

   The Content-Location value is not a replacement for the original
   requested URI; it is only a statement of the location of the resource
   corresponding to this particular entity at the time of the request.
   Future requests MAY use the Content-Location URI if the desire is to
   identify the source of that particular entity.

   A cache cannot assume that an entity with a Content-Location
   different from the URI used to retrieve it can be used to respond to
   later requests on that Content-Location URI. However, the Content-
   Location can be used to differentiate between multiple entities
   retrieved from a single requested resource, as described in section
   13.6.

   If the Content-Location is a relative URI, the URI is interpreted
   relative to any Content-Base URI provided in the response. If no
   Content-Base is provided, the relative URI is interpreted relative to
   the Request-URI.










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