You should not need to use a special unpack method for Turkish. Vietnamese, like Turkish, is based on Latin with many additional diacritics, and it does not need to change the way the strings are unpacked. If you are seeing the wrong characters show up when unpacking it's almost certainly because you pasted characters into the editor that used some character encoding other than UTF-8.

Turkish isn't an instance of Latin - it *inherits* from Latin in order to get the other transliterations like `ü`. Vietnamese does the same thing - you only need to specify the transliterations specific to your language. The way you set it up is perfectly correct; the only issue we need to resolve here is that there should be no need for a special unpack just for Turkish.