Interesting Features of CAS

Feature

Purpose

renew=true

Although CAS provides Single Sign-On (SSO), application developers can still force a user to present his/her credentials to CAS even if the user has already authenticated (please see Re-authentication or renew=true). This is called renew, and the feature is outlined in the CAS documentation on the CAS Protocol
Note: In CAS Server 3.1 or greater, this feature can be enforced by the CAS server itself. So, if you want CAS to present the login screen for your users regardless of whether or not the user has already authenticated, answer Yes next to the question, Requires Reauthentication on the CAS Registration form.

method=POST

CAS has a built-in mechanism to send responses via HTTP POST instead of HTTP Redirects for applications that require it. To enable it for your particular application, you should redirect to the CAS login page with an additional parameter:method=POST. For instance: 

https://auth.berkeley.edu/cas/login?method=POST&servce=https://something.berkeley.edu/login