In order to install a message catalog, the installation procedure shall supply the message catalog in a format readable by the msgfmt utility, which shall be invoked to compile the message catalog into an appropriate binary format on the target system.
Rationale: The original intent was to allow an application to contain the binary GNU MO format files. However, the format of these files is not officially stable, hence it is necessary to compile these catalogs on the target system. These binary catalogs may differ from architecture to architecture as well.
Implementations shall support the POSIX and C locales as specified in ISO POSIX (2003). Implementations may define additional locale categories not defined by that standard.
Note: Implementations choosing additional locale categories should be aware of ISO/IEC TR14652 and are advised not to choose names that conflict with that specification. If implementations provide locale categories whose names are part of the FDCC set of ISO/IEC TR14652, they should behave as defined by that specification.