Section 10,14: BN

 (Blank Control Editing)

 Causes embedded and trailing blanks to be ignored within a numeric
 input field.  Leading blanks are always ignored, and an all blank
 field is always treated as zero.

 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, blanks are ignored.