Each Fortran line has the following four fields:

    Statement label field           Columns 1-5
    Continuation indicator field    Column 6
    Statement field                 Columns 7-72 (if you specify
                                      the EXTEND_SOURCE compiler
                                      option or OPTIONS/EXTEND_SOURCE,
                                      statements extend to column 132)
    Sequence number field           Columns 73-80

  Note:  If you use the sequence number field, do not use tabs
  anywhere in the source line, or the compiler may interpret the
  sequence numbers as part of the statement field in your program.