Bidirectional Control - Yes

Yes is the designation for characters that actively alter the directionality of text in a bidirectional context, such as the Arabic and Hebrew scripts mixed with Western text. These control characters, including the left-to-right mark, right-to-left mark, and various embedding and override codes, are not visible themselves but instead signal how surrounding characters should be ordered. When this value applies, the character serves as a formatting instruction for software to switch or isolate directional runs, ensuring that strings like numbers, dates, or embedded quotes display correctly. Unlike characters with other directional classifications, these function purely as invisible markers, and their presence can change how neighboring text is rendered. Thus, Yes indicates a character whose primary role is to manage text flow, not to represent a glyph, making it essential for proper reading order in multilingual documents.