lang = 5 letters for Apple's Search API, am I missing something?

Question

Apple's search API documents specify:

lang =

The language, English or Japanese, you want to use when returning search results. Specify the language using the five-letter codename. For example: en_us.

The default is en_us (English).

examples: en_us, ja_jp

However, I cannot find this 5 letter standard codename. Are they just expecting a ISO 639-1 Code concatenated with a 2 letter country code?

Has anybody ran into this issue before?

Answer 1

As you can see the document below, en_us, ja_jp is not a "example" but the supported values for lang parameter key.

https://www.apple.com/itunes/affiliates/resources/documentation/itunes-store-web-service-search-api.html

This means, currently this api supports only these two langeages.

Hope this helps.