I keep a reference to some simple but painful task if you forget a common or something. I am new to Yii and this took awhile for me to figure out. Everything I read said do this or do that and not a single one worked for me. However, the following did.
This HowTo assumes that you have a smattering of ACL in general and of how the acl-extension works basically. It will introduce you into the abstract and give you a hint on how to use Business-Rules. If you have in-depth questions, please refer to the extension documentation.
Using ACL in an RBAC-manner cannot and should never obscure the fact that the underlying system is still ACL-based. In fact, the Business-Rules are just another layer in the permission-check plan.