What characters are permitted for translation keys in i18next?

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Translation keys in i18next can contain any Unicode character, including lowercase and uppercase letters, numbers, underscores, and hyphens. However, it is recommended to use only alphanumeric characters and underscores, to ensure compatibility with all platforms and formats. Special characters, such as spaces, symbols, and non-ASCII characters, may cause issues in some contexts. It is also good practice to keep the keys concise, clear, and consistent throughout the application.