The SU, SP, and S edit descriptors control leading signs for output. For normal output, without any specific sign specifiers, if a value is negative, a minus sign is printed in the first position to the left of the leftmost digit; if the value is positive, printing a plus sign depends on the implementation, but f77 omits the plus sign.
The following sign specifiers are available:
SP--If SP precedes a specification, a sign is printed.
SS--If SS precedes a specification, plus-sign printing is suppressed.
S--If S precedes a specification, the system default is restored. The default is SS.
SU--If SU precedes a specification, integer values are interpreted as unsigned. This is nonstandard. @
2000 FORMAT( SU, 16R, 8I10.8 )
The rules and restrictions for sign control are:
Sign-control specifiers apply to output only.
A sign-control specifier remains in effect until another sign-control specifier is encountered, or format interpretation is complete.
The S, SP, and SS specifiers affect only I, F, E, D, and G editing.
The SU specifier affects only I editing.