The developer first has to use in his code the PRISM module
(`use PRISM', see
oasis4/lib/psmile_oa4/src/prism.F90),
which declares all PRISM structures and PRISM integer named parameters
from oasis4/lib/common_oa4/include/prism.inc (data types, grid types, error codes,
etc.). The following routines then participate in the coupling
initialisation phase: