Hi! When I want to generate the font, the program asks how I want to generate the data: binary or compiled. Unfortunately I can't find any information about it. What is the difference and what are the effects of each shape?
TypeTool is a basic font editing program so it has limited support of OpenType (OT) features in modern OpenType fonts. When TypeTool imports a font, it stores OT features as a block in binary format. This block may contain the 'kern' OT feature with font kerning. TypeTool doesn't decompile features to show them in text format and therefore you cannot edit them and compile back on export. But you can change font kerning which then can be compiled on export.
So if you deleted a glyph or added at least one new glyph, OT features will be dropped without notice. The exported font will not include them. If you only changed contours in glyphs or some font info, so your edits didn't change the glyph set, old binary OT features will be exported back to the new font silently.
BUT if you changed kerning as well TypeTool issues this warning. Pressing "Binär" or "No" will export old binary OT features as they were imported without changes to the font kerning. Your changes to the kerning pairs will be lost. Pressing "Kompiliert" or "Yes" will drop binary OT features but will compile and export your new changes to the kerning. The exported font will not include OT features (except the 'kern' feature with kerning) as if you made changes to the glyph set.
Anyway, if you need to work with modern fonts including OT features, especially having support for complex scripts (like Arabic or Hebrew), you should better pay attention to modern apps like our FontLab 7.