s-o-1036 June 1994
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6.11. Lines
The Lines header content indicates the number of lines in
the body of the article:
Lines-content = 1*digit
The line count includes all body lines, including the signa-
ture if any, including empty lines (if any) at beginning or
end of the body. (The single empty separator line between
the headers and the body is not part of the body.) The
"body" here is the body as found in the posted article,
AFTER all transformations such as MIME encodings.
Reading agents SHOULD not rely on the presence of this
header, since it is optional (and some posting agents do not
supply it). They MUST not rely on it being precise, since
it frequently is not.
NOTE: The average line length in article bodies is
surprisingly consistent at about 40 characters,
and since the line count typically is used only
for approximate judgements ("is this too long to
INTERNET DRAFT to be NEWS sec. 6.11
read quickly?"), dividing the byte count of the
body by 40 gives an estimate of the body line
count that is adequate for normal use. This esti-
mate is NOT adequate if the body has been MIME
encoded... but neither is the Lines header, since
at least one major relayer will supply a Lines
header for an article that lacks one, and will not
consider the possibility of MIME encodings when
computing the line count.
NOTE: It would be better to have a Content-Size
header as part of MIME, so that body parts could
have their own sizes, and so that the units used
could be appropriate to the data type (line count
is not a useful measure of the size of an encoded
image, for example). Doing this is preferable to
trying to fix Lines.
UNRESOLVED ISSUE: Update on Content-Size?
Relayers SHOULD discard this header if they find it neces-
sary to re-encode the article in such a way that the origi-
nal Lines header would be rendered incorrect.
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#Diff to first older
--- ../rfc1036/Lines.out December 1987
+++ ../s-o-1036/Lines.out June 1994
@@ -1,5 +1,51 @@
-2.2.12. Lines
+6.11. Lines
- This contains a count of the number of lines in the body of the
- message.
+The Lines header content indicates the number of lines in
+the body of the article:
+
+ Lines-content = 1*digit
+
+The line count includes all body lines, including the signa-
+ture if any, including empty lines (if any) at beginning or
+end of the body. (The single empty separator line between
+the headers and the body is not part of the body.) The
+"body" here is the body as found in the posted article,
+AFTER all transformations such as MIME encodings.
+
+Reading agents SHOULD not rely on the presence of this
+header, since it is optional (and some posting agents do not
+supply it). They MUST not rely on it being precise, since
+it frequently is not.
+
+ NOTE: The average line length in article bodies is
+ surprisingly consistent at about 40 characters,
+ and since the line count typically is used only
+ for approximate judgements ("is this too long to
+
+INTERNET DRAFT to be NEWS sec. 6.11
+
+
+ read quickly?"), dividing the byte count of the
+ body by 40 gives an estimate of the body line
+ count that is adequate for normal use. This esti-
+ mate is NOT adequate if the body has been MIME
+ encoded... but neither is the Lines header, since
+ at least one major relayer will supply a Lines
+ header for an article that lacks one, and will not
+ consider the possibility of MIME encodings when
+ computing the line count.
+
+ NOTE: It would be better to have a Content-Size
+ header as part of MIME, so that body parts could
+ have their own sizes, and so that the units used
+ could be appropriate to the data type (line count
+ is not a useful measure of the size of an encoded
+ image, for example). Doing this is preferable to
+ trying to fix Lines.
+
+ UNRESOLVED ISSUE: Update on Content-Size?
+
+Relayers SHOULD discard this header if they find it neces-
+sary to re-encode the article in such a way that the origi-
+nal Lines header would be rendered incorrect.