The Binary Compatibility package provides a set of libraries compatible with the SunOS 4.x libraries. Therefore, even if the interface or behavior of a routine has changed in the Solaris 2.x release, user applications should not be affected when the Binary Compatibility Package is used.
The order of locales in the string returned by setlocale() differs between the SunOS 4.x and Solaris 2.x releases. This string is normally used by a subsequent call to setlocale(), and the order should not matter. Applications that rely on a specific order of locales may not be binary compatible.