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

Translated versions of locale display name elements: languages, scripts, territories, and variants.

{
  "main": {
    "myv": {
      "identity": {
        "language": "myv"
      },
      "localeDisplayNames": {
        "languages": {
          "myv": "эрзянь кель"
        }
      }
    }
  }
}