On Mon, Mar 20, 2023 at 4:48 PM Steffen Nurpmeso wrote: However note that even something like "uppercase this string" > cannot be done the right way, because a truly Unicode aware > operation needs to look at the entire string (sentence), because > there may be interdependencies that modify the result. If you are talking about downcasing Greek Σ, then it's true that always downcasing Σ to σ is inadequate. Unicode specifies that if the Σ appears before a space or punctuation mark, it downcases to ς instead. But this is not always correct. For example, if the string "ΦΙΛΟΣ." is the word "φιλοσ" (meaning 'beloved' or 'friend') at the end of a sentence, "φιλοσ." is the correct downcasing. But if it is the abbreviation for "φιλοσοφία", meaning "philosophy", then the correct downcasing is "φιλοσ." So getting this right is an AI-complete problem which neither Unicode nor ICU can solve.