Hi, Casefolding (Unicode Standard 3.13) is a more aggressive version of lowercasing. It's purpose to assist in the implementation of caseless mapping. For example, under lowercase "ß" -> "ß" but under casefolding "ß" -> "ss". I propose we add a casefold() method. So, case-insensitive matching should really be "one.casefold() == two.casefold()" rather than "one.lower() == two.lower()". Regards, Benjamin