Retrieving program-supplied default messages

All message-retrieving routines return the program-supplied default message text if the desired message cannot be retrieved for any reason. Program-supplied default messages are generally brief one-line messages that contain no message numbers in the text. Users who prefer these default messages can set the LC_MESSAGES category to the C locale or unset the NLSPATH environment variable. When none of the LC_ALL, LC_MESSAGES, or LANG environment variables are set, the LC_MESSAGES category defaults to the C locale.