Comment by ozgung

We created our own letters and our own rules. In 1928, long before code pages and computers.

The assumption that letters come in universal pairs is wrong. That assumption is the bug. You can’t assume that capitalization rules must be the same for every language implementing a specific alphabet. Those rules may change for every language. They do.

And not just capitalization rules. Auto complete, for instance, should respect the language as well. You can’t “correct” a French word to an English word. Localization is not optional when dealing with text.

> I just want to understand why the Turks decided to change this letter, and this letter only

Because Turkish uses a phonetic alphabet suited for Turkish sounds, based on latin letters. There are 8 vovels come in two subsets:

AIOU and EİÖÜ.

When you pair them with zip(), pairs are phonetically related sounds but totally different letters at the same time. Turkish also uses suffixes for everything, and vowels in these suffixes sometimes change between these two subgroups.

This design lets me write any word uniquely and almost correctly using the Turkish alphabet.

Dis dizayn lets mi rayt ani vörd yüniğkli end olmost koreğtkli yuzing dı törkiş alfabet.

Ö is the dotted version of O. İ is the dotted version of I. Related but different. Their lower case versions are logically (not by historical convention): öoiı. So we didn’t just wanted to change I, and only I. We just added dots. Since there are no Oö pair in any language our OoÖö vovels didn’t get the same attention. Same for our Ğğ and Şş.

I hope this answers the question.

Note that ASCII stands for "American Standard Code for Information Interchange". There's no expectation here that this is a suitable code for any language other than English, the de-facto language of the United States of America.