Authentication and Authorization events in Siteminder

Authentication Events
Authentication events occur when a user accesses a resource protected by a rule that includes an On-Auth event. Unlike Web Agent actions or authorization events, authentication events always apply to the entire realm. We can’t create an On-Auth rule that applies to a portion of a realm. Authentication events include the following:

On-Auth-Accept: Occurs if authentication was successful. This event may be used to redirect a user after a successful authentication.
On-Auth-Reject:Occurs if authentication failed for a user that is bound to a policy containing an On-Auth-Reject rule. This event may be used to redirect the user after a failed authentication.
On-Auth-Attempt: Occurs if the user was rejected because Siteminder does not know this user (an unregistered user, for example, can be redirected to register first).
On-Auth-Challenge: Occurs when custom challenge-response authentication schemes are activated (for example, a token code).
OnAuthUserNotFound – This event is only used to trigger Active Responses. This event should not be used to trigger any response other than an Active Response.


Authorization Events 
Authorization events will occur as Siteminder verifies whether or not a user is authorized to access a resource. As a rule action, an authorization event causes the Policy Server to fire a rule at a particular point in the authorization process. Authorization events include the following:

On-Access-Accept: Occurs when Siteminder successfully authorizes a user to access the resource.
On-Access-Reject: Occurs when Siteminder rejects a user because the user is not authorized to access the resource.

Source :http://vaibhav181.wordpress.com/2012/08/12/authentication-and-authorization-events-in-siteminder/