Intel® Fortran Compiler 17.0 Developer Guide and Reference
The BZ edit descriptor causes the processor to interpret all embedded and trailing blanks in numeric input fields as zeros. It takes the following form:
BZ
The input field ' 23 4 ' is interpreted as ' 23040'. If ' 23 4' is entered, the formatter adds one blank to pad the input to the six-digit integer format (I6), but this extra space is ignored, and the input is interpreted as ' 2304 '. The blanks following the E or D in real-number input are ignored, regardless of the form of blank interpretation in effect.
Suppose you enter 123 and press Enter in response to the following READ statement:
READ (*, '(I6)') n
The I/O system is looking for six characters to interpret as an integer number. You have entered only three, so the first thing the I/O system does is to pad the record 123 on the right with three blanks. If BZ editing is in effect, those three blanks are interpreted as zeros, and the record is equal to 123000.