İske imlâ alphabet

Additional characters that could not be found in Arabic and Persian were borrowed from the Chagatai language.

In 1920, it was replaced by the Yaña imlâ (which was not an Abjad, but derived from the same source).

[1] Based on the standard Arabic alphabet, İske imlâ reflected all vowels in the beginning and end of a word and back vowels in the middle of a word with letters, but front vowels in the middle of a word, as in most Arabic alphabets, were optionally reflected using harakat (diacritics on top of or below consonants).

While the user had to make a conversion of writing into pronunciation, somewhat akin to English, this allowed for more similar orthography between Turkic languages, because words looked more similar even when vowels vary, such as in cases of variations like ö to ü, o to u, or e to i. Yaña imlâ added separate letters for vowels and thus broke out with standard Arabic alphabets, but spelling followed no standard convention.

European and Russian loanwords were pronounced according to how they could be written with the İske imlâ, so that, for example, "equator" was spelled "ikwatur".