+The default is
+.Dq coalesce=1 .
+The default may be overridden by specifying
+.Dq coalesce=0 .
+The values
+.Dq off
+and
+.Dq false
+may be used in place of
+.Dq 0 .
+.El
+.Pp
+The following options all deal with file rotation and life-cycle management.
+The FILE ROTATION section describes this in detail.
+.Pp
+.Bl -tag -width "rotate=NAME_STYLE" -compact -offset indent
+.Pp
+.It rotate=NAME_STYLE
+Enables log file rotation and specifies the file naming scheme for rotated files.
+This option does not apply to ASL directories.
+Four styles are supported:
+.Pp
+.Bl -tag -width "local-basic" -compact -indent
+.It sec
+Rotated file names are of the form
+.Dq example.log.T1340607600 .
+The file names include the creation time of the file in seconds since the epoch.
+.Pp
+.It utc
+Rotated file names are in ISO 8601 extended format, for example
+.Dq example.log.2012-06-24T07:00:00Z .
+The file names includes its creation time as a UTC date and time.
+.Pp
+.It utc-basic
+Rotated file names are in ISO 8601 basic format, for example
+.Dq example.log.20120624T070000Z .
+The file names includes its creation time as a UTC date and time.
+.Pp
+.It local
+Rotated file names are in ISO 8601 extended format, for example
+.Dq example.log.2012-06-24T07:00:00-7 .
+The file names includes its creation time as date and time in the local time zone.
+The local timezone offset is included as a trailing part of the name.
+.Pp
+.It local-basic
+Rotated file names are in ISO 8601 basic format, for example
+.Dq example.log.20120624T070000-07 .
+The file names includes its creation time as date and time in the local time zone.
+The local timezone offset is included as a trailing part of the name.
+.Pp
+.It seq
+Rotated file names are of the form
+.Dq example.log.N
+where N is an integer sequence number.
+Files are re-numbered on each rotation so that the
+.Dq 0
+file is the most recent.
+.El
+.Pp
+If the option
+.Dq rotate
+appears without a value, the naming style defaults to
+.Dq "sec" .
+.Pp
+Note that using the local timezone for timestamped files may cause odd behavior on highly-mobile systems.
+.Nm aslmanager
+will delete files after a specified time-to-live (see below).
+The age of the file is determined by the file name.
+If files are created in different timezones but saved with a non-absolute timestamp,
+the age calculation may result in some files being considered older or newer than they are in reality.
+.Pp
+Also note that sequenced files (using the
+.Dq seq
+style) will initially be checkpointed using a file name containing a timestamp in seconds.
+.Nm aslmanager
+will re-sequence the files when it scans for checkpoint files.
+.Pp
+.It ttl=DAYS
+Specifies the number of days that older versions of rotated files should be allowed to remain in the filesystem.
+Rotated files older than this limit are deleted.
+.Pp
+.It dest=PATH
+By default, rotated files are left in the same directory as the original file.
+However, in some cases it may be useful to move the rotated versions to a different
+directory for archival or other reasons.
+If this option is specified,
+.Nm aslmanager
+will move files to the directory given by PATH.
+.Pp
+.It soft
+Makes
+.Nm syslogd
+ignore write errors when saving messages.
+Normally,
+.Nm syslogd
+will stop saving to a file or ASL directory after 5 consecutive write errors.
+.Pp
+.It compress
+Enables gzip file compression for rotated log files.
+When compressed, the extension
+.Dq .gz
+is appended to the file name.
+.Pp
+.It file_max=SIZE
+Limits the size of an active log file.
+SIZE may be an integer number of bytes, or the value may be followed by a single character
+.Dq k ,
+.Dq m ,
+or
+.Dq g
+(upper or lower case),
+to indicate a size limit in multiples of 1024 (kibibyte), 1048576 (mebibyte), or 1073741824 (gibibyte).
+If a file exceeds this limit, it is immediately checkpointed by
+.Nm syslogd
+and a new file is opened.
+Note that
+.Dq file_max
+specifies a size limit before file compression is performed if the
+.Dq compress
+option is also present.
+.Pp
+.It all_max=SIZE
+Specifies a size limit for the total of all rotated versions of a file.
+.Nm aslmanager
+will delete rotated files, oldest first, to reduce the total below the limit.
+SIZE may be specified in the same format as the file_max option.
+.El
+.Ss FILE ROTATION
+.Nm syslogd
+and
+.Nm aslmanager
+work together to automatically provide all the features of file rotation.
+However, it is useful to understand how the process works.
+This section describes the file rotation options that may be used in /etc/asl.conf
+or an ASL Output Module configuration file,
+together with a description of how the system works to support those features.
+.Pp
+If a file is marked for rotation,
+.Nm syslogd
+will close the file at the start of a new day or when the file exceeds its
+.Dq file_max
+size limit.
+At that point,
+.Nm syslogd
+renames the file and starts a new file to continue logging.
+The old file is renamed with the file's creation time included in its name.
+This operation is called checkpointing the file.
+.Pp
+For example,
+.Nm syslogd
+might close
+.Dq example.log
+and rename it
+.Dq example.log.T1340521200 ,
+1340521200 being the time that the file was created.
+It would then start a new
+.Dq example.log
+file and use it until midnight, when the cycle would be repeated.
+.Pp
+Files are normally checkpointed at midnight.
+If the system is sleeping or powered off, then files are checkpointed when
+the the first message of a new day (local time) is received.
+Files are also checkpointed if they exceed a size limit specified by a file_max option,
+and they may be checkpointed manually through options provided by the
+.Xr syslog 1
+and
+.Xr aslmanager 8
+utilities.
+The checkpointed file name always contains the file's creation time.
+If the options for the file include
+.Dq rotate=utc
+then the timestamp will be a UTC date and time string.
+.Dq rotate=local
+causes the timestamp to be the date and time in the current local timezone.
+Otherwise, the timestamp will be in seconds since the epoch.
+.Pp
+.Nm syslogd
+only performs the checkpointing operation.
+It closes old files, moves them out of the way, and starts writing new files.
+Most of the work of file rotation is done by the
+.Xr aslmanager 8
+utility.
+That includes moving files to a destination directory, compressing files,
+re-naming files according to one of the naming style options,
+deleting old files after they exceed their time-to-live,
+and checking file space usage.
+.Pp
+.Nm aslmanager
+normally runs once during system start-up, and once a day just after midnight.
+It may also be triggered occasionally by
+.Nm syslogd ,
+and it may be run manually.
+.Pp
+.Nm aslmanager
+scans for any checkpointed files created by
+.Nm syslogd
+and will rename the files (if required) to match the naming style specified by the
+.Dq rotate=NAME_STYLE