SUB (Substitute): A character that may be substituted for a
   character which is determined to be invalid or in error.
      ESC (Escape): A control character intended to provide code
   extension (supplementary characters) in general information
   interchange.  The Escape character itself is a prefix affecting the
   interpretation of a limited number of contiguously following
   characters.
      FS (File Separator), GS (Group Separator), RS (Record Separator),
   and US (Unit Separator): These information separators may be used
   within data in optional fashion, except that their hierarchical
   relationship shall be: FS is the most inclusive, then GS, then RS,
   and US is least inclusive.  (The content and length of a File, Group,
   Record, or Unit are not specified.)
      DEL (Delete): This character is used primarily to "erase" or
   "obliterate" erroneous or unwanted characters in perforated tape.
   (In the strict sense, DEL is not a control character.)

5.3 Graphic Characters

      SP (Space): A normally non-printing graphic character used to
   separate words.  It is also a format effector which controls the
   movement of the printing position, one printing position forward.
   (Applicable also to display devices.)

6. General Considerations

   6.1 This standard does not define the means by which the coded set is
   to be recorded in any physical medium, nor does it include any
   redundancy or define techniques for error control.  Further, this
   standard does not define data communication character structure, data
   communication formats, code extension techniques, or graphic
   representation of control characters.

   6.2 Deviations from the standard may create serious difficulties in
   information interchange and should be used only with full cognizance
   of the parties involved.

   6.3 The relative sequence of any two characters, when used as a basis
   for collation, is defined by their binary values.










 
RFC 20            ASCII format for Network Interchange      October 1969


   6.4 No specific meaning is prescribed for any of the graphics in the
   code table except that which is understood by the users.
   Furthermore, this standard does not specify a type style for the
   printing or display of the various graphic characters.  In specific
   applications, it may be desirable to employ distinctive styling of
   individual graphics to facilitate their use for specific purposes as,
   for example, to stylize the graphics in code positions 2/1 and 5/15
   into those frequently associated with logical OR (|) and logical NOT
   (252), respectively.

   6.5 The appendixes to this standard contain additional information on
   the design and use of this code.



         [ This RFC was put into machine readable form for entry ]
           [ into the online RFC archives by Robbie Bennet 9/99]