I1 : naming of variables, subroutines, modules
**********************************************

The IFS has a historical naming convention, which should be adhered to 
where sensible.

Variable naming 
================
* Local variables

 * integer : ``Ixxx``
 * real : ``Zxxx``
 * logical : ``LLxxx``
 * derived type : ``YLxxx``

* Argument variables

 * integer : ``Kxxxx``
 * real : ``Pxxx``
 * logical : ``LDxxx``
 * derived type : ``YDxxx``

* Name suffixes

 * L suffix corresponds to local / subdomain variables
 * G suffix corresponds to global / full-domain variables

Routine naming
==============

* setup routines should start with "su"
* TL and AD routines should end with tl and ad respectively

*Module naming*
New modules should end with _mod. The name of the file should match
the name of the module it contains (e.g. ``MODULE EINT`` should be in file eint_mod.F90)