RFC 1874 (rfc1874) - Page 3 of 6

SGML Media Types

RFC 1874                    SGML Media Types               December 1995


2.3.    SGML Sub-type Parameters

   The parameters for the Text/ and Application/SGML subtypes are
   defined below.

       charset     The charset parameter for Text/SGML is defined in
                   [RFC-1521], the valid values and their meaning are
                   registered by the Internet Assigned Numbers
                   Authority (IANA) [RFC-1590].  The default charset
                   value for all Text content-types is "us-ascii"
                   [RFC-1521].

                   The charset parameter is provided to permit non-
                   SGML capable systems to provide reasonable
                   behavior when Text/SGML defaults to Text/Plain.
                   SGML capable systems will use the SGML-bctf param-
                   eter.

       SGML-bctf   The SGML-bctf (SGML bit combination transformation
                   format) parameter describes the method used to
                   transform the entity's sequence of constant width
                   binary numbers (called "bit combinations" in [ISO
                   8879, 4.24]) into the octet stream contained in
                   the MIME body part.

                   Valid values for SGML-bctf are the BCTF notation
                   names defined in Annex C of [ISO-10744] and are
                   reproduced for convenience in the Appendix.  The
                   default value is "identity", i.e. perform no
                   transformation.

       SGML-boot   The SGML-boot parameter value is the content-ID of
                   a MIME body part (Application/Octet-stream) that
                   satisfies the requirements of the boot attribute
                   in [ISO-10744].  The Appendix contains a summary
                   of those requirements.  The SGML-boot parameter is
                   only applicable if the SGML entity is a document
                   entity.

3.      Security Considerations

   SGML entities contain information to be parsed and processed by the
   recipient's SGML system.  Those entities may contain and such systems
   may permit explicit system level commands to be execute while
   processing the data.  To the extent that an SGML system will execute
   arbitrary command strings recipients of SGML entities may be at risk.





Levinson                      Experimental