ANSI escape sequences are used to control text formatting and other output options on text terminals. In this context, ANSI refers to the ANSI X3.64 standard. It was replaced by ISO/IEC 6429, which is equivalent to ECMA-48. Most of these escape sequences start with the characters ESC. This sequence is called CSI for Control Sequence Introducer [. There is a single-character CSI as well. The ESC+[ two-character sequence is more often used than the single-character alternative, for details see C0 and C1 control codes. Devices supporting only ASCII, or which implement 8-bit code pages which use the 0x80 0x9F control character range for other purposes will recognize only the two-character sequence. Though some encodings use multiple bytes per character, in this topic all characters are single-byte.