@timbray I knew FORTRAN 77 decades ago. The fact that column offsets were important delimiters because of punch cards was quaint in a cool way.

IIRC
- Columns 1-5 were punch card number. Unused in the 1990s
- Column 6 was a continuation flag. If it was blank, it was a new line, but if it wasn’t then the statement from the previous line was continued on to this line
- Columns 7-75? Were the program statement
I think 76-80ish were some other reserved field. Maybe that was the punch card number and 1-5 was something else. It also was unused in the 1990s