AUDIT_SYSLOG_LEVEL Priority value definitions

The Database Reference for initialization parameter AUDIT_SYSLOG_LEVEL shows what priority levels are available but no definition as to what extent each level logs and does not log. Where can I find a concise definition of these levels ?

We are setting up the database to pass a PCI Security Audit and I need to know what the proper setting of the Priority should be to be able to satisfy auditing of the following requirements:

All access to cardholder data. 

All actions taken by any individual with root or administrative privileges. 

Use of identification and authentication mechanisms. 

All elevation of privileges.