Expert localization decisions for iOS/tvOS: when runtime language switching is needed vs system handling, pluralization rule complexity by language, RTL layout strategies, and string key architecture. Use when internationalizing apps, handling RTL languages, or debugging localization issues. Trigger keywords: localization, i18n, l10n, NSLocalizedString, Localizable.strings, stringsdict, plurals, RTL, Arabic, Hebrew, SwiftGen, language switching