Extended interrogation techniques
Extended interrogation techniques are less unique techniques, and more ways of applying other techniques, to add stress and fatigue to the questioning. Questioning of 20 hours per day, allowed by U.S. guidelines in Iraq,  might be perfectly legal in a single session, but, if done in many consecutive sessions, constitute sleep deprivation. The idea of the Geneva Conventions is that prisoners may not be treated worse than one's own civilians or prisoners; Article 53 of the Third Geneva Convention says "The duration of the daily labour of prisoners of war, ... shall not be excessive, and must in no case exceed that permitted for civilian workers in the district...Prisoners of war must be allowed, in the middle of the day's work, a rest of not less than one hour. This rest will be the same as that to which workers of the Detaining Power are entitled, if the latter is of longer duration."
Since there are no hard guidelines on rest, interrogators that try to be ethical develop working guidelines. Mackey said that his group in Afghanistan felt it was acceptable if the "interrogator took the exact same regime — slept, ate, [urinated], and took breaks on the same schedule as the prisoner — there was no way to argue we were treating prisoner any differently than we treated our own men." He considered using multiple interrogator techniques that allowed individual interrogators to rest to be outside his guidelines, and, even so, required that a team supervisor approve the extended techniques on a case-by-case basis. 
- "The Torture Question: Rules of Engagement", Frontline, Public Broadcasting System
- Chris Mackey & Greg Miller (2004), The Interrogators: inside the secret war against al Qaeda, Little, Brown & Co., ISBN 0-316-87112-5, pp. 287-289