Unicode Block - Specials

Specials is a small collection of fallback and control characters, including the replacement character (often shown as a hollow or solid question mark), the byte order mark (also used as a zero width no-break space), and the noncharacter U+FFFF, which is intended for internal use and never to be displayed or exchanged. These code points serve as sentinels for error handling, text normalization, and edge case detection in data streams, ensuring that systems can flag invalid or incomplete input rather than misinterpreting it as meaningful text.