- Source files with the .f suffix adhere to fortran fixed format standard
- the default indentation width is 1
- Source files with the .f90 suffix adhere to fortran free format standard
- the default indentation width is 3
- Each subroutine/function contains a comment section that explicitly states its purpose
- Each new paragraph in a source file starts with a comment line detailing the purpose of the following paragraph
- All public variables in a module have an abc_ prefix that is unique for that module.
- All variables/subroutines/functions/intrinsics etc. have lowercase names.
- the only exeception is a USE statement for modules that are defined in the same file in which they are used.