Columbia University Model Permission LettersThe Copyright Advisory Office (CAO) was established at Columbia University in January 2008, and its mission will surely evolve in the coming years. Its central function, however, is to address in an innovative, creative, and pragmatic manner the relationship between copyright law and the work of the university community. In all of our research, teaching, and service, we are constantly creating and using a rich variety of materials that are protected under copyright law.