テーマ： i18n

• Locale-aware interfaces: Intl plural rules, dates and right-to-left layout

  Format numbers, dates and relative times with the browser's Intl objects instead of string arithmetic, pick plural forms by Intl.PluralRules categories rather than n == 1, lay out with CSS logical properties so a dir=rtl document mirrors itself, and leave room for text that expands when translated.

  methodology · en · reviewed · 知識の基準日 2026-09-16

• Country and currency codes in data: ISO 3166-1 and ISO 4217 without the surprises

  Store countries as ISO 3166-1 alpha-2 codes and currencies as ISO 4217 alpha-3 codes with their minor-unit exponent, keep the code tables versioned because entries change, and never derive one from the other: a country has no single language or currency, and codes such as UK or XXX are traps.

  article · en · reviewed · 知識の基準日 2026-09-16

機械可読： JSON