5.2 Content Guidelines

• Sign Conventions Enthalpy is defined as negative; fluxes are positive downward.

• Implicit None All modules will include an implicit none statement, immediately following the use statements. This implies that all variables must be explicitly typed.

• Prologues Each module, subroutine and function will include a prologue for use with the ProTeX auto-documentation script (http://dao.gsfc.nasa.gov/software/protex). This will be used to make a code reference document.

• I/O Error Conditions I/O statements which need to check an error condition, i.e. namelist read statements, should use the iostat = <integer variable> construct instead of end and err.

• Intent All dummy arguments should include the INTENT clause in their declaration.

• Conditionals Conditionals based on $<$ 0. or $>$ 0. should be avoided.

• Physical Constants Values of physical constants should not be hardwired into the executable portion of a code. Constants should be defined in a single module as named, full-precision parameters.

• All units should be in MKS; CGS conversions should be avoided. Diagnostics and other fields that do not affect the model integration may be in other units.