| /// The decoder for this encoding is the same as the decoder for gb18030. |
| /// The encoder side of this encoding is GBK with Windows code page 936 euro |
| /// sign behavior. GBK extends GB2312-80 to cover the CJK Unified Ideographs |
| /// Unicode block as well as a handful of ideographs from the CJK Unified |
| /// Ideographs Extension A and CJK Compatibility Ideographs blocks. |
| /// |
| /// Unlike e.g. in the case of ISO-8859-1 and windows-1252, GBK encoder wasn't |
| /// unified with the gb18030 encoder in the Encoding Standard out of concern |
| /// that servers that expect GBK form submissions might not be able to handle |
| /// the four-byte sequences. |
| /// |
| /// [Index visualization for the two-byte sequences](https://encoding.spec.whatwg.org/gb18030.html), |
| /// [Visualization of BMP coverage of the two-byte index](https://encoding.spec.whatwg.org/gb18030-bmp.html) |
| /// |
| /// The encoder of this encoding roughly matches the Windows code page 936. |
| /// The decoder side is a superset. |