Allows to build partial, smaller libraries for special purposes. By default, all modules are built. The switches are fairly coarse, controlling large modules. Basic services cannot be turned off.
Building with any of these options does not guarantee that the ICU build process will completely work. It is recommended that the ICU libraries and data be built using the normal build. At that time you should remove the data used by those services. After building the ICU data library, you should rebuild the ICU libraries with these switches customized to your needs.
Definition in file uconfig.h.