Definition: sign

A symbol that identifies a positive or negative number. In digital form, it is either a separate character or part of the byte. In ASCII, the sign is kept in a separate character typically transmitted in front of the number it represents
(+ and - is 2B and 2D in hex).

In EBCDIC, the minus sign can be stored as a separate byte (hex 60), or, more commonly, as half a byte (+ and - is C and D in hex), which is stored in the high-order bits of the least significant byte. For packed decimal, it is in the low-order bits of the least significant byte.