EDIT The DEL character (U+007F) has no special meaning in Unicode, but most systems treat it the same as the ASCII DEL character. Some Unix systems treat the DEL character as a backspace or forward-delete signal.

 rtg 

EDIT DEL is the ASCII Delete character. This value corresponded to all-bits-on in 7-bit ASCII, although of course it's not an all-bits-on value anymore.

The all-bits-on value has a history that parallels that of the all-bits-off value (see the entry on U+0000). In the early days of telegraphy, paper tape was used to store messages before transmission (composing offline to paper tape and then using the tape for transmission saved bandwidth). If the sending operator punched a code in error, the only way to delete it on tape was to punch out all the holes in the offending row. This would result in an all-bits-on code being sent over the wire. For this reason, most encodings treated all-bits-on as an indication of a composition error and receiving equipment was designed to treat it as a no-op, the same as the null (all-bits-off) character.

On computers, however, Delete became a synonym for destructive backspace, wiping out the previous character.

 199.245.29.3  cherlin