The LANG environment variable determines which message catalogs are used. All message catalogs are installed by default. If LANG is not defined or is assigned an unsupported locale, en_US message catalogs are used. This topic introduces a list of available locales.
English (en_US) is the default national language. Following installation, you can set the NLSPATH so that messages are displayed in a different language. See Enabling the XL C/C++ error messages.