cldr-localenames-full/main/frr/languages.json

Translated versions of locale display name elements: languages, scripts, territories, and variants. (all locales)

{
  "main": {
    "frr": {
      "identity": {
        "version": {
          "_cldrVersion": "44.1"
        },
        "language": "frr"
      },
      "localeDisplayNames": {
        "languages": {
          "frr": "Nordfriisk"
        }
      }
    }
  }
}