Country codes should be defined as ISO 3166 Alpha-2

[leovegoda]

Country is mentioned twice in the schema. In the ixp_list it is described as "ISO country code where the IXP is located" and in switch it is "Country the switch is located in".

The ISO 3166 standard offers three code types: Alpha-2, Alpha-3, and numeric. It also offers both and English and French short name, which some readers might confuse for a code.

Users of the JSON data can normalize it. But it would be helpful if the schema helped developers and others choose the format expected by data users: Alpha-2.

We should specify Alpha-2 as the code element to use to reduce the opportunities for inaccurate analysis based on a mixture of Alpha-2 codes and country names in exports.