1. Introduction

   The purpose of the Structured Data eXchange Format (SDXF) is to
   permit the interchange of an arbitrary structured data block with
   different kinds of data (numerical, text, bitstrings).  Because data
   is normalized to an abstract computer architecture independent
   "network format", SDXF is usable as a network interchange data
   format.

   This data format is not limited to any application, the demand for
   this format is that it is usable as a text format for word-
   processing, as a picture format, a sound format, for remote procedure
   calls with complex parameters, suitable for document formats, for
   interchanging business data, etc.

   SDXF is self-describing, every program can unpack every SDXF-data
   without knowing the meaning of the individual data elements.

   Together with the description of the data format a set of functions
   will be introduced.  With the help of these functions one can create
   and access the data elements of SDXF.  The idea is that a programmer
   should only use these functions instead of maintaining the structure
   by himself on the level of bits and bytes.  (In the speech of
   object-oriented programming these functions are methods of an object
   which works as a handle for a given SDXF data block.)

   SDXF is not limited to a specific platform, along with a correct
   preparation of the SDXF functions the SDXF data can be interchanged
   (via network or data carrier) across the boundaries of different
   architectures (specified by the character code like ASCII, ANSI or
   EBCDIC and the byte order for binary data).

   SDXF is also prepared to compress and encrypt parts or the whole
   block of SDXF data.