Applications that are aware of FNS can expect the namespace to be arranged according to the FNS policies, and applications that bind names in the FNS namespace are expected to follow these policies.
Applications use FNS three ways:
Applications can be direct clients of the FNS interface and policies. Application-level utilities such as the file system, the printing service, and the desktop tools (calendar manager, file manager) are examples of clients that use the FNS interface directly.
Applications can use FNS through existing interfaces. A significant proportion of FNS use is through existing application programming interfaces. For example, consider a UNIX application that obtains a file name that it later supplies to the UNIX open() function. With FNS support for resolution of file names, the application need not be aware that the strings it deals with are composite names rather than the traditional local path names. Many applications can thereby support the use of composite names without modification.
Systems can export the FNS interface. Naming systems, such as DNS and X.500, and naming systems embedded in other services, like the file system and printing service, are examples of naming systems that export the FNS interface.