The DBCACNX extension applies only to the Connect function and only when the Connect-type option specifies a combined logon and connect. Use of the Connection-extension will be rejected if the Connect-type option specifies a separate logon and run. When used, it should be pointed to by the Extension Pointer DBCAREA field before invoking Connect. The Extension Pointer should be zeroed after the Connect function to prevent subsequent functions from attempting to use it.
The DBCACNX can be used only to provide information required by CLI for third party Logon (SSO). Third party logon is supported only on Windows.