Historically, Java has used old/obsolete ISO 639 language codes for Hebrew/Indonesian/Yiddish languages to maintain compatibility. From Java 17, the default codes are the current codes. For example, "he" is now the language code for "Hebrew" instead of "iw". A new system property has also been introduced to revert to the legacy behavior. If `-Djava.locale.useOldISOCodes=true` is specified on the command line, it behaves the same way as the prior releases.