grafana/public/app/core/internationalization/constants.ts

export const ENGLISH_US = 'en-US';
export const FRENCH_FRANCE = 'fr-FR';
export const SPANISH_SPAIN = 'es-ES';
export const PSEUDO_LOCALE = 'pseudo-LOCALE';

export const DEFAULT_LOCALE = ENGLISH_US;

export const VALID_LOCALES: string[] = [ENGLISH_US, FRENCH_FRANCE, SPANISH_SPAIN, PSEUDO_LOCALE];