that representation.

4.1.1.  AUTH_TYPE

   The AUTH_TYPE variable identifies any mechanism used by the server to
   authenticate the user.  It contains a case-insensitive value defined
   by the client protocol or server implementation.

   For HTTP, if the client request required authentication for external
   access, then the server MUST set the value of this variable from the
   'auth-scheme' token in the request Authorization header field.







 
RFC 3875                    CGI Version 1.1                 October 2004


      AUTH_TYPE      = "" | auth-scheme
      auth-scheme    = "Basic" | "Digest" | extension-auth
      extension-auth = token

   HTTP access authentication schemes are described in RFC 2617 [5].

4.1.2.  CONTENT_LENGTH

   The CONTENT_LENGTH variable contains the size of the message-body
   attached to the request, if any, in decimal number of octets.  If no
   data is attached, then NULL (or unset).

      CONTENT_LENGTH = "" | 1*digit

   The server MUST set this meta-variable if and only if the request is
   accompanied by a message-body entity.  The CONTENT_LENGTH value must
   reflect the length of the message-body after the server has removed
   any transfer-codings or content-codings.

4.1.3.  CONTENT_TYPE

   If the request includes a message-body, the CONTENT_TYPE variable is
   set to the Internet Media Type [6] of the message-body.

      CONTENT_TYPE = "" | media-type
      media-type   = type "/" subtype *( ";" parameter )
      type         = token
      subtype      = token
      parameter    = attribute "=" value
      attribute    = token
      value        = token | quoted-string

   The type, subtype and parameter attribute names are not
   case-sensitive.  Parameter values may be case sensitive.  Media types
   and their use in HTTP are described section 3.7 of the HTTP/1.1
   specification [4].

   There is no default value for this variable.  If and only if it is
   unset, then the script MAY attempt to determine the media type from
   the data received.  If the type remains unknown, then the script MAY
   choose to assume a type of application/octet-stream or it may reject
   the request with an error (as described in section 6.3.3).

   Each media-type defines a set of optional and mandatory parameters.
   This may include a charset parameter with a case-insensitive value
   defining the coded character set for the message-body.  If the






 
RFC 3875                    CGI Version 1.1                 October 2004


   charset parameter is omitted, then the default value should be
   derived according to whichever of the following rules is the first to
   apply:

      1. There MAY be a system-defined default charset for some
         media-types.

      2. The default for media-types of type "text" is ISO-8859-1 [4].

      3. Any default defined in the media-type specification.

      4. The default is US-ASCII.

   The server MUST set this meta-variable if an HTTP Content-Type field
   is present in the client request header.  If the server receives a
   request with an attached entity but no Content-Type header field, it
   MAY attempt to determine the correct content type, otherwise it
   should omit this meta-variable.

4.1.4.  GATEWAY_INTERFACE

   The GATEWAY_INTERFACE variable MUST be set to the dialect of CGI