Very early versions of MS-DOS replaced the backslash with these glyphs on the display to make it possible to display them by programs that only understood 7-bit ASCII (other characters such as the square brackets were replaced as well, see ISO 646, Windows Codepage 932 (Japanese Shift JIS), and Codepage 949 (Korean)).
非常早期的MS-DOS版本在显示器上用这些字形替代了反斜杠，以便只能理解7位ASCII的程序显示它们（其他字符如方括号也被替换，见ISO/IEC 646、Windows Codepage 932 (Japanese Shift JIS)和Codepage 949 (Korean)）。