Standard keyboards transmit this code when the Ctrl and Z keys are pressed simultaneously (Ctrl+Z, often documented by convention as ^Z).
In CP/M, 86-DOS, MS-DOS, PC DOS, DR-DOS, and their various derivatives, the SUB character was also used to indicate the end of a character stream,[citation needed] and thereby used to terminate user input in an interactive command line window (and as such, often used to finish console input redirection, e.g. as instigated by the command COPY CON: TYPEDTXT.TXT).
[citation needed] In such cases, it is often termed a "soft" EOF, as it does not necessarily represent the physical end of the file, but is more a marker indicating that "there is no useful data beyond this point".
Many file format standards (e.g. PNG or GIF) include the SUB character in their headers to perform precisely this function.
In Unix-like operating systems, this character is typically used in shells as a way for the user to suspend the currently executing interactive process.
Control+Z was one of a handful of keyboard sequences chosen by the program designers at Xerox PARC to control text editing.