To:       "Al Neuman"@Mad-Host,
               Sam.Irving@Other-Host
     Message-ID:  <some.string@SHOST>

     A.3.3.  About as complex as you're going to get

     Date     :  27 Aug 76 0932 PDT
     From     :  Ken Davis <KDavis@This-Host.This-net>
     Subject  :  Re: The Syntax in the RFC
     Sender   :  KSecy@Other-Host
     Reply-To :  Sam.Irving@Reg.Organization
     To       :  George Jones <Group@Some-Reg.An-Org>,
                 Al.Neuman@MAD.Publisher
     cc       :  Important folk:
                   Tom Softwood <Balsa@Tree.Root>,
                   "Sam Irving"@Other-Host;,
                 Standard Distribution:
                   /main/davis/people/standard@Other-Host,
                   "standard.dist.3"@Tops-20-Host>;
     Comment  :  Sam is away on business. He asked me to handle
                 his mail for him.  He'll be able to provide  a
                 more  accurate  explanation  when  he  returns
                 next week.
     In-Reply-To: <some.string@DBM.Group>, George's message
     X-Special-action:  This is a sample of user-defined field-
                 names.  There could also be a field-name
                 "Special-action", but its name might later be
                 preempted
     Message-ID: <4231.629.XYzi-What@Other-Host>






     August 13, 1982              - 39 -                      RFC #822
 

 
     Standard for ARPA Internet Text Messages


     B.  SIMPLE FIELD PARSING

          Some mail-reading software systems may wish to perform  only
     minimal  processing,  ignoring  the internal syntax of structured
     field-bodies and treating them the  same  as  unstructured-field-
     bodies.  Such software will need only to distinguish:

         o   Header fields from the message body,

         o   Beginnings of fields from lines which continue fields,

         o   Field-names from field-contents.

          The abbreviated set of syntactic rules  which  follows  will
     suffice  for  this  purpose.  It describes a limited view of mes-
     sages and is a subset of the syntactic rules provided in the main
     part of this specification.  One small exception is that the con-
     tents of field-bodies consist only of text:

     B.1.  SYNTAX


     message         =   *field *(CRLF *text)

     field           =    field-name ":" [field-body] CRLF

     field-name      =  1*<any CHAR, excluding CTLs, SPACE, and ":">

     field-body      =   *text [CRLF LWSP-char field-body]


     B.2.  SEMANTICS

          Headers occur before the message body and are terminated  by
     a null line (i.e., two contiguous CRLFs).

          A line which continues a header field begins with a SPACE or
     HTAB  character,  while  a  line  beginning a field starts with a
     printable character which is not a colon.

          A field-name consists of one or  more  printable  characters
     (excluding  colon,  space, and control-characters).  A field-name
     MUST be contained on one line.  Upper and lower case are not dis-
     tinguished when comparing field-names.







     August 13, 1982              - 40 -                      RFC #822
 

 
     Standard for ARPA Internet Text Messages