As I can tell so far, fontconfig picks font in an "A-Z" order...so ja_JP locale won't need to modify anything. maybe the only rule it needs to apply is to substitute "Noto Sans CJK Sans" (some characters are half-width instead of proportional) to "Noto Sans Mono CJK Sans". And I'm preparing a fix...well 470MB + 89MB are a little huge for my bandwidth...I need them to fix the generate_specfile.sh Marguerite