| HTML Entity (dec) | ？ |
| HTML Entity (hex) | ？ |
| UTF-8 (hex) | 0xefbc9f / 0xef 0xbc 0x9f (3 bytes) |
| UTF-8 (dec) | 239, 188, 159 (3 bytes) |
| UTF-16-BE (hex) | 0xff1f / 0xff 0x1f (2 bytes) |
| UTF-16-BE (dec) | 255, 31 (2 bytes) |
| UTF-32-BE (hex) | 0xff1f / 0x00 0x00 0xff 0x1f (4 bytes) |
| UTF-32-BE (dec) | 0, 0, 255, 31 (4 bytes) |
| C/C++/Java source code | "\uff1f" |
| Python source code | "\uff1f" |