Gatekeepers can also have a dual role as developers of operating systems and device manufacturers, including any technical functionality that such a device may have. For example, a gatekeeper that is a manufacturer of a device can restrict access to some of the functionalities in that device, such as near-field-communication technology, secure elements and processors, authentication mechanisms and the software used to operate those technologies, which can be required for the effective provision of a service provided together with, or in support of, the core platform service by the gatekeeper as well as by any potential third-party undertaking providing such service.