{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "$id": "BASEURL/country.json",
    "title": "country",
    "description": "Country",
    "type": "object",
    "properties": {
        "countryName": {
            "type": "string",
            "description": "Name of the country."
        },
        "countryA2": {
            "type": "string",
            "description": "ISO-3166 alpha-2 code."
        },
        "countryA3": {
            "type": "string",
            "description": "ISO 3166-1:2013 alpha-3"
        },
        "countryNumber": {
            "type": "string",
            "description": "ISO-3166 numeric code."
        }
    },
    "required": ["countryA3"],
    "additionalProperties": false
}

{
    "countryName": "poland",
    "countryA2": "pl",
    "countryA3": "pol",
    "countryNumber": "616"
}