Read only role for user that also needs to view logs - what privilege?

I have an audit user that has read only role and they discovered that they can't view the logs (version 5.0 623373).

so I want to keep the read only role but add the privilege to view the VIC logs (home > admin > system logs) which more then likely creating a new Audit Role with read only with system log viewing.

what is the privilege that will give them as minimal as possible privilege that I can add to a new audit role to view the system logs?  (not ESXi host logs but virtual center logs).