Interchange converters—7-bit
This converter provides conversion between internal code and 7-bit standard interchange formats (fold7).
The fold7 name identifies encodings that can be used to pass text data through 7-bit mail protocols. The encodings are based on ISO2022.
The fold7 converters convert characters from a code set to a canonical 7-bit encoding that identifies each character. This type of conversion is useful in networks where clients communicate with different code sets but use the same character sets. For example:
| Code set conversion | Description |
|---|---|
| IBM-850 <—> ISO8859-1 | Common Latin characters |
| IBM-932 <—> IBM-eucJP | Common Japanese characters |
The following escape sequences designate standard code sets:
| Escape sequence | Standard code set |
|---|---|
| 01/11 02/04 04/00 | GL JIS X0208.1978-0. |
| 01/11 02/04 02/08 04/01 | GL left half of GB2312.1980-0. |
| 01/11 02/08 04/02 | GL 7-bit ASCII or left half of ISO8859-1. |
| 01/11 02/14 04/01 | GL right half of ISO8859-1. |
| 01/11 02/14 04/02 | GL right half of ISO8859-2. |
| 01/11 02/14 04/03 | GL right half of ISO8859-3. |
| 01/11 02/14 04/04 | GL right half of ISO8859-4. |
| 01/11 02/14 04/06 | GL right half of ISO8859-7. |
| 01/11 02/14 04/07 | GL right half of ISO8859-6. |
| 01/11 02/14 04/08 | GL right half of ISO8859-8. |
| 01/11 02/14 04/12 | GL right half of ISO8859-5. |
| 01/11 02/14 04/13 | GL right half of ISO8859-9. |
| 01/11 02/08 04/09 | GL right half of JIS X0201.1976-0. |
| 01/11 02/08 04/10 | GL left half of JIS X0201.1976. |
| 01/11 02/04 04/02 | GL JIS X0208.1983-0. |
| 01/11 02/04 02/08 04/02 | GL JIS X0208.1983-0. |
| 01/11 02/04 02/08 04/00 | GL JISX0208.1978-0. |
| 01/11 02/05 02/15 03/01 M L 06/09 06/02 06/13 02/13 03/08 03/05 03/00 00/02 | GL right half of IBM-850 unique characters. Characters common to ISO8859-1 do not use this escape sequence. |
| 01/11 02/05 02/15 03/02 M L 06/09 06/02 06/13 02/13 07/05 06/04 06/03 04/10 05/00 00/02 | GL Japanese) IBM-udcJP) user-definable characters. |
| 01/11 02/04 02/08 04/03 | GL KSC5601-1987. |
| 01/11 02/04 02/09 03/00 | GL CNS11643-1986-1. |
| 01/11 02/04 02/10 03/01 | GL CNS11643-1986-2. |
| 01/11 02/05 02/15 03/00 M L 05/05 05/04 04/06 02/13 03/07 00/02 | UCS-2 encoded as base64; used only for those characters not encoded by any of the other 7-bit escape sequences listed above. |
When converting from a code set to fold7, the escape sequence used to designate the code set is chosen according to the order listed. For example, the JISX0208.1983-0 characters use 01/11 01/04 04/02 as the designation.