Fixed_and_Tab_Format

 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.

Additional information available:

Fixed           Tab