Authentication Context for the OASIS
Security Assertion Markup Language
Section 3.3 explains the extension mechanism
currently the console only shows the auth context classes described in this document.
MS ADFS can uses 'urn:federation:authentication:windows' (see http://msdn.microsoft.com/en-us/library/hh599318.aspx).
As this auth context class can not be configured in OpenAM through the console SP-initiated auth does not trigger integrated Windows Auth on the IdP (ADFS) side.