1) Who - your code of text editor or function of operations system - interpret the control codes 0x00 till 0x1f (e.g. LineFeed 0x0a)? If these codes have glyphs in .ttf-files, and we wanna see these glyphs in text editor, changes should be done in text editor or in system function?
2) The same question for control codes 0x80 till 0x9f.
3) Opposite question: who interpret code 0x20 (Space) as mark to bring text to new line? To change code of Space to another one (e.g. to 0x49), where changes should be done?
4) To interpret code of old regular letter (e.g. 0x48) as control code (e.g. as LineFeed), where changes should be done?
5) For symbols 0x00 till 0x7f, what are the ways to use 7-bits encoding table with classical .ttf-files without converting text into 8-bits encoding?