Each newsgroup directory contains a file named
containing one-line summaries of articles in that group.
Fields are separated by tabs,
and any tabs or newlines in the original articles headers
have been replaced with spaces.
The fields are,
in order:
1.
article number (file name)
2.
subject
3.
author
4.
date
5.
message-id
6.
references
7.
byte count
8.
line count
9...
optionally other headers,
as arranged locally
(none are supplied by the database maintenance software,
as shipped).
The line-count and references fields may be empty.
If the optional other headers are present,
they include their header keyword and colon;
if they are absent entirely,
the tab after the line-count field may also be absent.
The file is maintained in numerical order,
by article number.
At the time of writing
(late 1992),
the lines in an overview file are typically 150-300 characters long,
and an overview file for a typically busy group
is often 30,000 bytes to 60,000 bytes long,
with notable exceptions exceeding 500,000 bytes.
EXAMPLES
A few lines from one overview file,
with tabs displayed as `(Tb' and lines continued after `\'.
Written by Geoff Collyer
as part of the C News project.
BUGS
The contents of
the line-count field
should not be believed
and are really pretty worthless yet popular.
There is some confusion about whether
the order and content of the first eight fields is a local decision,
or a standard.
It's intended to be a standard; please do not mess with it.
All, repeat all,
local variations should be done by adding the optional fields
at the end,
and those fields must
include their header keywords (and colons) to make them self-identifying.
