Just guessing the reason: ÖZIL or Özil is correct in his native German language. There's no öÖ or ı in English but öÖ is widespread in European languages, whereas the usage of specifically İ or ı is very limited (in most cases i is just capitalized as I). Btw Ö is often anglicized and transliterated to Oe in English since we don't have that sound or umlauts in it but it doesn't look great. I'm also guessing printing ÖZIL in his native German instead of ÖZİL in Turkish at Fener will be for the sake of consistency and possibly marketing reasons. It would be an issue if whenever a player arrived they had to localize the name, ex. Maks Kruza or whatever hehe