ASCII Character ␚

Originally intended for use as a transmission control character to indicate that garbled or invalid characters had been received. It has often been put to use for other purposes when the in-band signaling of errors it provides is unneeded, especially where robust methods of error detection and correction are used, or where errors are expected to be rare enough to make using the character for other purposes advisable. In DOS, Windows, CP/M, and derivatives of Digital Equipment Corporation operating systems, it is used to indicate the end of file, both when typing on the terminal, and sometimes in text files stored on disk.