Changes When Titlecased

Changes When Titlecased is a binary character attribute that indicates whether a character’s appearance or mapping alters when it is transformed into titlecase, which is the capitalization style used for the first letter of a word in a title. Specifically, this property is true for characters that have a distinct titlecase mapping different from their uppercase mapping, such as the digraph characters like dz, which become Dz, or ligatures like ff, which become Ff. For most alphabetic characters, uppercase and titlecase forms are identical, so the property is false, but for certain multi-part or context-dependent characters, the titlecase form combines both case variants, often represented as a sequence of two code points. This distinction matters for proper text case conversion in applications like word processors or search engines, ensuring that the first letter of a title is correctly rendered without losing the character’s inherent dual-case nature.