/etc/logcheck/ignore.d.server/cron is in logcheck-database 1.3.17.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | ^\w{3} [ :0-9]{11} [._[:alnum:]-]+ (/usr/bin/)?crontab\[[0-9]+\]: \([[:alnum:]-]+\) LIST \([[:alnum:]-]+\)$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ (/usr/bin/)?crontab\[[0-9]+\]: \([[:alnum:]-]+\) REPLACE \([[:alnum:]-]+\)$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ (/usr/bin/)?crontab\[[0-9]+\]: \([[:alnum:]-]+\) (BEGIN|END) EDIT \([[:alnum:]-]+\)$
^\w{3} [ :0-9]{11} [._[:alnum:]-]+ CRON\[[0-9]+\]: nss_ldap: reconnect(ing|ed) to LDAP server(\.\.\.| after [0-9]+ attempt\(s\))$
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