Bit of an edgecase as I know of exactly one RP using this (Item Addon Pack, uses öäü)
This RP uses regex to cover a lot of items and refrences öÖäÄüÜ by their ASCII codes in the regex
This is the line in the .properties for this item
nbt.display.Name=iregex\:(.*\ |^)(Fl[\\u00D6\\u00F6]te|Flute)(\ .*|$)
The Item in the image would be named "Flöte", though the regex would allow case INsesetive spelling as well as "Flute"
Bit of an edgecase as I know of exactly one RP using this (Item Addon Pack, uses öäü) This RP uses regex to cover a lot of items and refrences öÖäÄüÜ by their ASCII codes in the regex
This is the line in the .properties for this item
nbt.display.Name=iregex\:(.*\ |^)(Fl[\\u00D6\\u00F6]te|Flute)(\ .*|$)
The Item in the image would be named "Flöte", though the regex would allow case INsesetive spelling as well as "Flute"