Rok Zerdin completed a Fluent UI migration for the Move To and Copy To menu items in the thunderbird/thunderbird-l10n repository, focusing on enhancing localization readiness and user interface consistency. By leveraging FTL and applying user interface design principles, Rok aligned these menu actions with the Fluent design system, ensuring a uniform experience across different locales. The work involved updating interface elements to support future localization efforts and maintaining clear traceability through detailed commit messages and bug references. While the scope was limited to a single feature over one month, the migration laid groundwork for broader Fluent adoption in Thunderbird’s localization workflows.