Confusing Session terminology

Hullo all, K, I'm totaly frustrated on this one ... the documentation for session_start states: "Note: If you are using cookie-based sessions, you must call session_start() before anything is output to the browser." So does this mean that if I have turned off cookie-based sessions I can call session_start anywhere I want? Even if output is already sent?? In my experience no .. I am not using cookie-based session, yet I still get the typical error message of output before headers .. which I would normally expect since i do have output prior. As a result, shouldn't the documentation then state that I must call session_start before any output is sent? irregardless to cookie-based or not??? cause it points to that fact!!