As you see this layout has several extra letters. The alphabet of Türk OK! has no new characters but instead a whole new layout. On the one hand it is following the international layout as far as possible. On the other hand İ and I are switched because of a simple reason: typing is mostly done in lower case so in lower case the internationally used i will appear instead of ı. I assume the original Turkish layout was chosen to minimize expenditure in production. Last but not least the ergonomical aspect: following the international layout will make it easy to switch between various layouts.

International English

International English