Changes When NFKC Casefolded

Changes When NFKC Casefolded is a binary character attribute that indicates whether a given code point’s full casefolded form, after applying the NFKC normalization process, differs from its original character. In practical terms, it flags characters whose appearance or meaning might transform when text is both casefolded and compatibility normalized, such as certain ligatures, superscripts, or symbols that decompose into multiple characters. Software using this property can predict that a string containing such a character will not remain stable under these transformations, which is crucial for consistent searching, sorting, or password handling. This property specifically highlights cases where the combination of casefolding and compatibility mapping yields a result that is not identical to the source, enabling developers to identify potentially surprising behavior in text processing.