...
RETRIEVE,
NUMBER = 1/to/50,
AREA = 076/-015/050/045,
GRID = 0.18/0.18,
ACCURACY = 16,
TARGET = "mars_ens_[date]_[time]+[step].[number]",
CLASS = OD,
TYPE = PF,
DATE = -5,
TIME = 06,
STREAM = ENFO,
EXPVER = 1,
STEP = 6/to/36/by/1,
LEVTYPE = ML,
LEVELIST = 1/to/91137,
PARAM = Q/T/U/V/LNSP
...