# Localization

> Route Apple-platform localization tasks to the correct Knowledge Contracts -- String Catalog (.xcstrings) mechanics, compiler-driven extraction and the string-literal requirement it depends on, translator comments, the New/Needs Review/Translated/Stale states, explicit keys vs. value-as-key, and manually-managed entries; the localized-string API surface (String(localized:), LocalizedStringResource for deferred cross-process resolution, LocalizedStringKey and SwiftUI's implicit Text literal localization, Text(verbatim:), AttributedString(localized:), format specifiers, NSLocalizedString); plural and device variation, the CLDR categories with other required, substitutions, and legacy .stringsdict; Locale and language resolution (current vs. autoupdatingCurrent, preferredLanguages vs. preferredLocalizations, Locale.Language/Locale.Region, CFBundleDevelopmentRegion, the .lproj fallback chain); layout-direction and RTL APIs including SF Symbols' name-driven mirroring; and localized resources (InfoPlist.xcstrings,

- Skill: `caglarbaranbora/localization` (Agent Skill)
- Install (CLI): `npx skillmds@latest add caglarbaranbora/localization`
- Raw SKILL.md: https://api.skillmd.com/api/skills/caglarbaranbora/localization/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: caglarbaranbora (https://skillmd.com/u/caglarbaranbora)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/caglarbaranbora/localization

---


# 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