C1 controls
The C1 controls are the control characters (code positions 128-159 decimal) which are defined by ISO/IEC 6429:1992 and are part of the ISO-8859 and other encodings. They are not often used, and in otherwise equivalent Microsoft character sets (e.g., Windows 1252) they are replaced by printing characters. It is common in both the web and e-mail for the character set to be announced as an ISO-8859 encoding but actually be in a Windows encoding, including the printable characters where these controls are located in the official standards, making it unsafe for software to even attempt to interpret them as control characters even though that is what the standards technically say to do in such cases. Because of their rarity of use, there is little agreement on their exact meaning and implementation.
| Hex | Dec | Abbreviation | Name | Description and uses |
|---|---|---|---|---|
| 80 | 128 | PAD | Padding Character | Not part of ISO/IEC 6429. |
| 81 | 129 | HOP | High Octet Preset | Not part of ISO/IEC 6429. |
| 82 | 130 | BPH | Break Permitted Here | Follows a graphic character where a line break is permitted. |
| 83 | 131 | NBH | No Break Here | Follows a graphic character where a line break is not permitted. |
| 84 | 132 | IND | Index | Moves the active position one line down. |
| 85 | 133 | NEL | Next Line | Yet another line ending. |
| 86 | 134 | SSA | Start of Selected Area | |
| 87 | 135 | ESA | End of Selected Area | |
| 88 | 136 | HTS | Horizontal Tabulation Set | Sets a horizontal tab stop. |
| 89 | 137 | HTJ | Horizontal Tabulation with Justification | Sets a horizontal tab stop and indicates text should be justified out to the stop. |
| 8A | 138 | VTS | Vertical Tabulation Set | Sets a vertical tab stop. |
| 8B | 139 | PLD | Partial Line Down | Moves the active position down to a position suitable for subscripts, or undoes PLU. |
| 8C | 140 | PLU | Partial Line Up | Moves the active position up to a position suitable for superscripts, or undoes PLD. |
| 8D | 141 | RI | Reverse Index | Moves the active position one line up. |
| 8E | 142 | SS2 | Single-Shift 2 | Indicates that the next code only should be interpreted in the G2 character set. |
| 8F | 143 | SS3 | Single-Shift 3 | Indicates that the next code only should be interpreted in the G3 character set. |
| 90 | 144 | DCS | Device Control String | Introduces a device control sequence, which is terminated by ST (0X9C). |
| 91 | 145 | PU1 | Private Use 1 | |
| 92 | 146 | PU2 | Private Use 2 | |
| 93 | 147 | STS | Set Transmit State | |
| 94 | 148 | PCH | Cancel Character | Backspace and cancel the previous character. |
| 95 | 149 | MW | Message Waiting | |
| 96 | 150 | SPA | Start of Protected Area | |
| 97 | 151 | EPA | End of Protected Area | |
| 98 | 152 | SOS | Start of String | Introduces a control string, which is terminated by ST (0X9C). |
| 99 | 153 | SGCI | Single Graphic Character Introducer | Not part of ISO/IEC 6429. |
| 9A | 154 | SCI | Single Character Introducer | Followed by a single printing character or format effector. Meaning uncertain. |
| 9B | 155 | CSI | Control Sequence Introducer | |
| 9C | 156 | ST | String Terminator | Marks the end of control sequences introduced by several C1 codes. |
| 9D | 157 | Operating System Command | Introduces an operating system command, which is terminated by ST (0X9C). | |
| 9E | 158 | PM | Privacy Message | Introduces a privacy message, which is terminated by ST (0X9C). |
| 9F | 159 | APC | Application Program Command | Introduces an application program command, which is terminated by ST (0X9C). |
