usr.sbin/cron/README

This is Vixie cron 3.0. This version fixes all known security bugs.
Further it implements crontab -e.
I moved cron from /usr/libexec to /usr/sbin where most daemons are
that are run from rc. That also gets rid of the ugly path crond
used to have in ps(1) outputs. Further I renamed it to cron, as
Paul Vixie likes it and is done by NetBSD.

NOTE VERY WELL THE FOLLOWING:

1) Systems crontab changed. Every users crontab resides in /var/cron
   *EXCEPT* root's. This is a special crontab as it resides in
   /etc. Further it is the *ONLY* crontab file in which you specify
   usernames. See /usr/src/etc/crontab. This is also done by BSDI's
   BSD/386 as far as I know (they provided the patches for it anyway)
2) So you *must* delete root's crontab and reinstall the copy
   in /etc from /usr/src/etc.
   'Must' is to much: the old installed crontab will work but cron
   will also try to 'run' /etc/crontab.
3) Last but not least: cron's logging is now done via syslog. Note
   that logging by cron is done lowercase when it logs about itsself
   and uppercase when it logs user events, like installing a new crontab.
   The default logfile file is the same as before:
        syslog.conf:cron.*      /var/cron/log

-Guido