Do Not Use Columns 73-80 in Your Source File
If you encounter problems with unmatched parentheses or quotation
marks or illegal continuation characters, the problem may be that you
are not adhering to the Fortran conventions for column format. You
need to be careful about which columns contain which characters. If
you violate the rules for column format you can get obscure errors.
Here is a summary of the format:
Column Contents
-------- ---------------------------------------------
1 'C' (indicating a Comment) or the first digit
of a statement number.
2 to 5 Remaining digits of a statement number.
6 Non-blank character indicates a continuation
of the previous line.
7 to 72 Program statements.
73 to 80 Must be blank!