Programming style is a matter of taste and can lead to long lasting religious wars. There's no wrong or right way. Do that which seems natural to you.

• Use the Fortran 90 free-format form. There are tricks you can use for header files for portable use from either Fortran 77 fixed-format or Fortran 90 free-format.

• Liberal use of <TABS> for indentation of code blocks.

• Use comments liberally to document the code. Fortran 90 allows statements to have trailing comments.

• Add implicit none as the first statement (after module USE statements). This enforces strong type declarations and code safety. This was common to most Fortran 77 compilers, but was not officially part of the standard until Fortran 90.

• Use entity-oriented declarations instead of attribute-oriented declarations. For example:

  	real, dimension(20), save :: val
  	real, save :: xval
  	real, dimension(10) :: aval
  

  instead of

  	real val, xval, aval
  	dimension val(20), aval(10)
  	save val, xval
  

  The obvious advantages are that you can quickly see all the attributes for a given variable.

• Use underscores (`_') instead of spaces within in variable names. Fortran does not use white space as keyword delimiters, but may, like most other languages, do so in the future.

• Variable & routine names can be longer than 8 characters (and less than 32 characters), thus promoting descriptive names.

• If a routine has more than 1 argument, give the dummy arguments sensible names, and use the keyword feature of Fortran 90. For example:

  subroutine subr(in, out)

  then call with

  call subr(in=xxx, out=yyy)

  or equivalently called as

  call subr(out=yyy, in=xxx)

  this hides any subsequent changes to the user interface (by making successive arguments optional and testing for them).