control codes are transparent to Unicode and their meanings are left to higher-level protocols. Besides these, Unicode include additional format effector characters besides these, such as marks, embeds, isolates and pops for explicit bidirectional formatting, and the zero-width joiner and non-joiner for controlling ligature use. However these are given the general category (format) rather than . See also Control Pictures ANSI escape code Footnotes References The Unicode Standard C0 Controls and Basic Latin C1 Controls and Latin-1 Supplement Control Pictures The Unicode Standard, Version 6.1.0, Chapter 16: Special Areas and Format Characters ATIS Telecom Glossary 2007 De litteris regentibus C1 quaestiones septem or Are C1 characters legal in XHTML 1.0? W3C I18N FAQ: HTML, XHTML, XML and Control Codes International register of coded character sets to be used with escape sequences Control characters de:Steuerzeichen