Section 10,15: BZ

 (Blank Control Editing)

 Causes embedded and trailing blanks to be treated as zeros within a
 numeric input field.  (Leading blanks are always ignored.)

 It affects all subsequent I, O, Z, F, E, D, and G editing (in the
 same FORMAT statement) during the execution of an output statement.

 If the OPEN statement is not used or it is used and BLANK='ZERO' is
 specified, blanks are converted to zeros.  If the OPEN statement is
 used and either BLANK='NULL' is specified or the BLANK keyword is
 omitted, nonleading blanks are treated as zeros.

 An all blank field is always treated as zero.