Comment 3 for bug 1492568

While English is not widely spoken in Indonesia as a proportion of it's population, it is the standard language of business and the professions, and among Indonesia's urban middle class.

Probably 3-5% of Indonesia's 250 million people use English on a daily basis, twice the population of Singapore.

The en_ID locale conforms to Indonesian standards relating to country codes, currency, time and date formats.

The en_ID locale was developed by Yayasan Teknologi Terbuka Indonesia (Indonesian Open Technology Foundation).

http://yatti.id/doku.php/en/en_id-indonesian-english-project