Provided by: inn2_2.7.2~20240212-1build3_amd64 bug

NAME

       expire.ctl - Configuration file for article expiration

DESCRIPTION

       The file pathetc/expire.ctl is the default configuration file for expire and expireover,
       which read it at start-up.  It serves two purposes: it defines how long history entries
       for expired or rejected articles are remembered, and it determines how long articles
       stored on the server are retained.

       Normally, if all of the storage methods used by the server are self-expiring (such as
       CNFS), all lines except the "/remember/" setting (described below) are ignored.  This can
       be changed with the -N option to expire or expireover.

       Blank lines and lines beginning with a number sign ("#") are ignored.  All other lines
       should be in one of two formats.  The order of the file is significant, and the last
       matching entry will be used.

       The first format specifies how long to keep history entries for articles that aren't
       present in the news spool.  These are articles that have either already expired, or
       articles which the server rejected (when remembertrash is set to true in inn.conf).  There
       should be one and only one line in this format, which looks like:

           /remember/:<days>

       where <days> is a decimal number that specifies the minimum number of days a history
       record for a given Message-ID is retained (from its original posting time), regardless of
       whether the article is present in the spool.  (History entries for articles still present
       in the spool are always retained.)  Setting it to "never" means history records will be
       retained forever, "0" means history records for articles not present in the spool will be
       purged when expiry programs run.  (This is notably useful in the case you need re-
       injecting articles no longer present in your news spool but considered as duplicate,
       because still present in history: you'll have to set "/remember/" to "0", run the expire
       process for instance via news.daily called with the same parameters as in crontab plus
       "notdaily", and undo the change in expire.ctl.  All previously rejected or removed
       articles will then not be considered as duplicate if their Message-ID is proposed.)

       The primary reason to retain a record of old articles is in case a peer offers old
       articles that were previously accepted but have already expired.  Without a history record
       for such articles, the server would accept the article again and readers would see
       duplicate articles.  Articles older than a certain number of days won't be accepted by the
       server at all (see artcutoff in inn.conf(5) and the -c flag in innd(8)), and this setting
       should probably match that time period to ensure that the server never accepts duplicates.
       As the default value for artcutoff is "10" days, it means that "/remember/" should be set
       to "11" days in order to take into account articles whose posting date is one day into the
       future.

       Most of the lines in this file will be in the second format, which consists of either four
       or five colon-separated fields:

           <pattern>:<flag>:<min>:<default>:<max>

       if groupbaseexpiry is true in inn.conf (the default), and otherwise:

           <classnum>:<min>:<default>:<max>

       All lines must be in the correct format given the current setting of groupbaseexpiry, and
       therefore the two formats cannot co-exist in the same file.

       Normally, a rule matches a newsgroup through the combination of the <pattern> and <flag>
       fields.  <pattern> is a uwildmat-style pattern, specifying the newsgroups to which the
       line is applied.  Note that the last matching entry will be used, so general patterns
       (such as defaults for all groups where <pattern> is "*") should appear at the beginning of
       the file before more specific settings.

       The <flag> field can be used to further limit newsgroups to which the line applies, and
       should be chosen from the following set:

           M   Only moderated groups
           U   Only unmoderated groups
           A   All groups
           X   Remove the article from all groups it appears in

       One of "M", "U", or "A" must be specified.  "X" should be used in combination with one of
       the other letters, not by itself.

       An expiration policy is applied to every article in a newsgroup it matches.  There is no
       way to set an expiration policy for articles crossposted to groups you don't carry that's
       different than other articles in the same group.  Normally, articles are not completely
       deleted until they expire out of every group to which they were posted, but if an article
       is expired following a rule where <flag> contains "X", it is deleted out of all newsgroups
       to which it was posted immediately.  (If that behaviour is wanted for all rules, you may
       want to give the -e flag to expireoverview.)

       If groupbaseexpiry is instead set to false, there is no <pattern> and <flag> field and the
       above does not apply.  Instead, there is a single <classnum> field, which is either a
       number matching the storage class number specified in storage.conf or "*" to specify a
       default for all storage classes.  All articles stored in a storage class will be expired
       following the instructions in the line with a matching <classnum>, and when articles are
       expired, they're always removed from all groups to which they were posted.

       The remaining three fields are the same in either format, and are used to determine how
       long an article should be kept from its original arrival time (unless the -p flag is
       passed to expire(8) or expireover(8), in which case its original posting time is used).
       Each field should be either a decimal number of days (fractions like "8.5" are allowed,
       but remember that articles are only removed when expire or expireover is run, normally
       once a day by news.daily) or the word "never".

       The middle field, <default>, will be used as the expiration period for most articles.  The
       other two fields, <min> and <max>, only come into play if the article requests a
       particular expiration date with an Expires header field.  Articles with an Expires header
       field will be expired at the date given in that header field, subject to the constraints
       that they will be retained at least <min> days and no longer than <max> days.

       If <min> is set to "never", no article matching that line will ever be expired.  If
       <default> is set to "never", no article matching that line without an explicit Expires
       header field will ever be expired.  If <max> is set to "never", Expires header fields will
       be honored no matter how far into the future they are.

       One should think of the fields as a lower bound, the default, and an upper bound.  Since
       most articles do not have an Expires header field, the second field is the most important
       and most commonly applied.

       Articles that do not match any expiration rule will not be expired, but this is considered
       an error and will result in a warning.  There should always be a default line (a line with
       a <pattern> of "*" and <flag> of "A", or a line with a <classnum> of "*"), which can
       explicitly state that articles should never expire by default if that's the desired
       configuration.  The default line should generally be the first line of the file (except
       for "/remember/") so that other expiration rules can override it.

       It is often useful to honor the Expires header field in articles, especially those in
       moderated groups.  To do this, set <min> to zero, <default> to whatever normal expiration
       you wish, and <max> to "never" or some large number, like "365" days for a maximum article
       life of a year.

       To ignore any Expires header field, set all three fields to the same value.

EXAMPLES

       When groupbaseexpiry is true (the default):

           # Keep expired article history for 11 days, matching artcutoff
           # plus one.
           /remember/:11

           # Most articles stay for two weeks, ignoring Expires header fields.
           *:A:14:14:14

           # Accept Expires header fields in moderated newsgroups for up to
           # a year, and retain moderated newsgroups for a bit longer.
           *:M:1:30:365

           # Keep local newsgroups for a long time and local project
           # newsgroups forever.
           example.*:A:1:90:90
           example.project.*:A:never:never:never

       When groupbaseexpiry is false, for class-based expiration:

           # Keep expired article history for 11 days, matching artcutoff
           # plus one.
           /remember/:11

           # Set a default expiration of seven days and honour Expires header
           # fields within reasonable limits.
           *:1:7:35

           # Class 0 is retained for two weeks and honor Expires header fields
           # within reasonable limits.
           0:1:14:65

HISTORY

       Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews.  Converted to POD by Russ
       Allbery <eagle@eyrie.org>.

SEE ALSO

       expire(8), expireover(8), inn.conf(5), innd(8), libinn_uwildmat(3), news.daily(8),
       storage.conf(5).