s-o-1036 June 1994

5.4. Subject

The  Subject header's content (the "subject" of the article)
is a short phrase describing the topic of the article:

     Subject-content  = [ "Re: " ] nonblank-text

Encoded words MAY appear in this header.

If the article is a followup, the subject SHOULD begin  with
"Re: "  (a  "back reference").  If the article is not a fol-
lowup, the subject MUST not begin  with  a  back  reference.
Back references are case-insensitive, although "Re: " is the
preferred form.  A followup  agent  assisting  a  poster  in
preparing a followup SHOULD prepend a back reference, UNLESS
the subject already begins with one.  If the  poster  deter-
mines  that  the topic of the followup differs significantly
from what is described in the subject, a new, more  descrip-
tive,  subject  SHOULD  be  substituted (with no back refer-
ence).  An article whose subject begins with a  back  refer-
ence  MUST  have a References header referencing the precur-
sor.

     NOTE: A back reference  is  FOUR  characters,  the
     fourth being a blank.  RFC 1036 was confused about
     this.  Observe also that only ONE  back  reference
     should be present.

     NOTE:  There  is a semi-standard convention, often
     used, in which a subject change is flagged by mak-
     ing the new Subject-content of the form:

          new topic (was: old topic)

     possibly  with  "old  topic"  somewhat  truncated.
     Posters wishing to  do  something  like  this  are
     urged  to  use  this exact form, to simplify auto-
     mated analysis.

For historical reasons, the  subject  MUST  not  begin  with
"cmsg " (note that this sequence ends with a blank).

     NOTE:  Some  old  news  software  takes  a subject
     beginning with "cmsg " as an indication  that  the
     article is a control message (see sections 6.6 and
     7).  This mechanism is obsolete  and  undesirable,
     but accidental triggering of it is still possible.

The subject SHOULD be terse.  Posters SHOULD avoid trying to
cram  their  entire  article into the headers; even the sim-
plest query usually benefits  from  a  sentence  or  two  of

INTERNET DRAFT to be        NEWS                    sec. 5.4


elaboration  and  context, and the details of header display
vary widely among reading agents.

     NOTE: All-in-the-subject  articles  are  sometimes
     the  result of misunderstandings over the interac-
     tion protocol of a posting agent.  Posting  agents
     might wish to give special attention to the possi-
     bility that a poster specifying a very  long  sub-
     ject  might have thought he was typing the body of
     the article.

--- ../rfc1036/Subject.out          December 1987
+++ ../s-o-1036/Subject.out          June 1994
@@ -1,11 +1,66 @@
-2.1.4.  Subject
+5.4. Subject
 
-    The "Subject" line (formerly "Title") tells what the message is
-    about.  It should be suggestive enough of the contents of the
-    message to enable a reader to make a decision whether to read the
-    message based on the subject alone.  If the message is submitted in
-    response to another message (e.g., is a follow-up) the default
-    subject should begin with the four characters "Re:", and the
-    "References" line is required.  For follow-ups, the use of the
-    "Summary" line is encouraged.
+The  Subject header's content (the "subject" of the article)
+is a short phrase describing the topic of the article:
+
+     Subject-content  = [ "Re: " ] nonblank-text
+
+Encoded words MAY appear in this header.
+
+If the article is a followup, the subject SHOULD begin  with
+"Re: "  (a  "back reference").  If the article is not a fol-
+lowup, the subject MUST not begin  with  a  back  reference.
+Back references are case-insensitive, although "Re: " is the
+preferred form.  A followup  agent  assisting  a  poster  in
+preparing a followup SHOULD prepend a back reference, UNLESS
+the subject already begins with one.  If the  poster  deter-
+mines  that  the topic of the followup differs significantly
+from what is described in the subject, a new, more  descrip-
+tive,  subject  SHOULD  be  substituted (with no back refer-
+ence).  An article whose subject begins with a  back  refer-
+ence  MUST  have a References header referencing the precur-
+sor.
+
+     NOTE: A back reference  is  FOUR  characters,  the
+     fourth being a blank.  RFC 1036 was confused about
+     this.  Observe also that only ONE  back  reference
+     should be present.
+
+     NOTE:  There  is a semi-standard convention, often
+     used, in which a subject change is flagged by mak-
+     ing the new Subject-content of the form:
+
+          new topic (was: old topic)
+
+     possibly  with  "old  topic"  somewhat  truncated.
+     Posters wishing to  do  something  like  this  are
+     urged  to  use  this exact form, to simplify auto-
+     mated analysis.
+
+For historical reasons, the  subject  MUST  not  begin  with
+"cmsg " (note that this sequence ends with a blank).
+
+     NOTE:  Some  old  news  software  takes  a subject
+     beginning with "cmsg " as an indication  that  the
+     article is a control message (see sections 6.6 and
+     7).  This mechanism is obsolete  and  undesirable,
+     but accidental triggering of it is still possible.
+
+The subject SHOULD be terse.  Posters SHOULD avoid trying to
+cram  their  entire  article into the headers; even the sim-
+plest query usually benefits  from  a  sentence  or  two  of
+
+INTERNET DRAFT to be        NEWS                    sec. 5.4
+
+
+elaboration  and  context, and the details of header display
+vary widely among reading agents.
+
+     NOTE: All-in-the-subject  articles  are  sometimes
+     the  result of misunderstandings over the interac-
+     tion protocol of a posting agent.  Posting  agents
+     might wish to give special attention to the possi-
+     bility that a poster specifying a very  long  sub-
+     ject  might have thought he was typing the body of
+     the article.