Short Answer - when ADS-B was commissioned.
Techincally it is not even Identificatiion Services Terminated but Identification Terminated - even though you are still Identified - makes sense doesn't it?! [EDIT: I see that is what you wrote TQ, but have heard the services part included as well]
Many who have to say this mouthful protested when we found out about it (no consultation that I recall), but were basically dismissed.
So if you hear Identification Terminated when leaving a control step, chances are you are still Identified - you are just not getting a service unless you request it (i.e. RIS).
(Call me stupid - but I think if a pilot hears Identification Terminated they probably think they are no longer Radar Identified)
Last edited by Shitsu_Tonka; 3rd Sep 2006 at 01:57.