There is a growing body of writings devoted to the ethical use of digital editing in photojournalism. In the United States, for example, the National Press Photographers Association (NPPA) established a Code of Ethics which promotes the accuracy of published images, advising that photographers "do not manipulate images [...] that can mislead viewers or misrepresent subjects." Infringements of the Code are taken very seriously, especially regarding digital alteration of published photographs, as evidenced by a case in which Pulitzer prize-nominated photographer Allan Detrich resigned his post following the revelation that a number of his photographs had been manipulated.