retrieve,
    class=od,
    type=fcmax,
    stream=sfmm,
    expver=0001,
    repres=gg,
    levtype=sfc,
    param=167,
    date=19911001,
    fcmonth=02/03/04,
    time=0000,
    number=0/1/2/3/4,
    domain=g,
    system=02,
    method=01,
    source="mod.cl.surface",
    target="data.reference"