Localization — Foundations Skill

Purpose

Route Apple-platform localization implementation tasks to the minimum required Knowledge Contracts. v1 covers how an app's user-facing strings and resources are extracted, stored, varied, and resolved across languages and regions -- not Xcode project configuration, translator XLIFF workflow, runtime content translation, source-copy style rules, value formatting, or RTL visual design. Baseline is Xcode 16+ with an iOS 17+ API surface; String Catalogs impose no deployment-target cost, since .xcstrings compiles to .strings/.stringsdict at build time.

Routing

Load only the contracts relevant to the task. All paths relative to knowledge/localization/.

• Creating or populating a .xcstrings String Catalog; extraction and the literal requirement; translator comment:; New/Needs Review/Translated/Stale states; explicit keys vs. value-as-key; manually-managed entries; "Don't Translate"; migrating a .strings/.stringsdict table -> string-catalogs-and-extraction.md
• Calling String(localized:), LocalizedStringResource, LocalizedStringKey, Text/Text(verbatim:), AttributedString(localized:), or NSLocalizedString; format specifiers; the locale: parameter -> localized-string-apis.md
• Varying a string by count or device; CLDR plural categories; substitutions; .stringsdict; ^[...](inflect: true) -> plural-and-device-variations.md
• Locale.current/autoupdatingCurrent; preferredLanguages/preferredLocalizations; Locale.Language/Locale.Region; CFBundleDevelopmentRegion; the .lproj fallback chain -> locale-and-language-resolution.md
• RTL layout; \.layoutDirection; flipsForRightToLeftLayoutDirection; semanticContentAttribute; effectiveUserInterfaceLayoutDirection; SF Symbols mirroring; characterDirection; RTL pseudolanguages -> layout-direction-and-rtl-apis.md
• InfoPlist.xcstrings/InfoPlist.strings; CFBundleDisplayName/CFBundleName; .lproj structure; localizing assets; Bundle.module/defaultLocalization; Bundle.localizedString(forKey:value:table:) -> localized-resources-and-infoplist.md

Never load more than the contracts relevant to the specific question.

Stop Conditions

Stop and report if the requested topic has no matching Knowledge Contract in knowledge/localization/ -- do not guess or fall back to general knowledge.

• Adding a language to an Xcode project and the .xcloc/XLIFF export-and-import round trip — owned by xcode
• The iOS 18 Translation framework (TranslationSession, .translationTask, .translationPresentation) — Excluded; real and documented, so neither fabricate guidance for it nor claim it does not exist
• Source-copy wording, capitalization, punctuation, and international representation/formatting — owned by style-guide
• Date, time, number, and measurement formatting — owned by foundation
• RTL visual-design decisions — owned by human-interface-guidelines
• App Shortcuts phrase and AppEnum localization — owned by app-intents
• App Store Connect localized metadata, APNs loc-key/loc-args payloads, macOS/watchOS/tvOS-specific behavior — Excluded
• Apple publishes no .xcstrings schema -- never assert its JSON field names