The SIGN clause specifies the position and representation of the
operational sign.
General Format
Syntax Rules
The SIGN clause is allowed only with input, output and update
fields whose pictures contain the character "S".
This clause is allowed only with elementary items.
General Rules
It is recommended that the SEPARATE option be used when the SIGN
clause is specified in a screen description. If the SEPARATE option is not
specified, a sign denoted by "S" in a PICTURE clause appears as an overpunch.