There seems to be a discrepancy in the documentation for Criteria-Based Sharing Rules.
The Guide to Sharing Architecture (and other sources) states that:
"Only Manual Share Records can be created on standard objects".
Yet, the help section: https://help.salesforce.com/HTViewHelpDoc?id=security_sharing_cbs_about.htm&language=en_US
states: "You can create criteria-based sharing rules for accounts, opportunities, cases, contacts, leads, campaigns, and custom objects."
I'm studying for certification and need clarification.