rsbackup.cron manpage says hourly/daily/weekly/monthly must be set, but script complains if they are

[pm215]

The rsbackup.cron manpage says:

   Configuration is read from /etc/rsbackup/defaults.  This is a shell script fragment and it should define the following variables:

   hourly

   daily

   weekly

   monthly
          Define the list of hosts to back up at a given frequency.  Use the special string _all to back up all hosts.

[etc]

but the script itself will complain "WARNING: obsolete configuration found in /etc/rsbackup/defaults" if any of those four are set.

I guess that the manpage should say that these are obsolete configuration variables, that they're ignored, and what the new syntax is for achieving the equivalent effect.