One of the core services in the 1EdTech OneRoster standard. This service is used to identify the set of learning and teaching resources that are required by a Class, Course, and/or User (the information about the Class, Course, and User would have been supplied using the 1EdTech OneRoster Rostering Service). The defined web service takes the form of JSON payloads exchanged by the communicating systems. This service uses the identifier for the resource. The resource could be obtained using systems/tools/applications that use the 1EdTech Common Cartridge/Thin Common Cartridge specification. At present this service is used extensively in the K-12/schools education sector.