Organizational affiliations of the creators of works are important to a variety of stakeholders, including academic administrators, funders, publishers, repository managers, software developers, rights agencies and individual researchers. Identifying and tracking these affiliations can be challenging, as organizations may be known by a variety of names and may have schools or research centers well-known on their own. An organizational identifier--a unique, persistent and public Uniform Resource Identifier (URI) associated with the organization that is resolvable globally over networks via specific protocols--provides the means to both find and identify an organization accurately and to define the relationships among its sub-units. This report presents new modeling of organizations that others can adapt for their own uses. This report focuses on organizational identifiers from the perspective of academic institutions. Their ranks and reputation often determine their success in obtaining funding and attracting or retaining faculty. Identifiers provide the "glue" for institutions and funder systems to support comparing and ranking the outputs of the research process; assessing the impact of grants between institutions and their funders; and tracking and collating publications between researchers and their publishers. The report outlines a number of scenarios where the International Standard Name Identifier (ISNI) can be used to disambiguate organizations, including real-world examples.