The locales directory contains:
The locales file (locales.dat), which maps locale names to languages, character sets, and collating sequences.
The message directory, which contains localized error messages for Open Client and Open Server products, organized by language name.
language_name subdirectories, which are included to provide compatibility with previous versions of Open Client and Open Server software. These directories contain localized message files organized by character set.
unicode directory, which contains error message files for system management utilities.