JDK-8363887 : Release Note: Remove the `java.locale.useOldISOCodes` System Property
  • Type: Sub-task
  • Component: core-libs
  • Sub-Component: java.util:i18n
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • OS: generic
  • CPU: generic
  • Submitted: 2025-07-22
  • Updated: 2025-07-25
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tbdUnresolved
Description
The support for the `java.locale.useOldISOCodes` system property has been removed. Introduced in JDK 17, this property allowed users to revert to the legacy ISO 639 language codes for Hebrew, Indonesian, and Yiddish. The property was deprecated in JDK 25, and as of JDK 26, specifying it has no effect and results in a warning message at runtime.