LocaleISOData contains the following table, isoLanguageTable which consists of the 2-letter and 3-letter ISO 639 language codes (specifically, the 639-1 and 639-2/T codes).

In order to proactively manage this table, it should be updated with the most up-to-date ISO 639 data: http://www.loc.gov/standards/iso639-2/php/code_list.php.

In addition, the test data used in Bug4175998Test.java is outdated (since 1999), and should be updated with the current data (which will include significant language code changes).