def _rectify_identifier(station, textprod):
    """Rectify the station identifer to IEM Nomenclature."""
    station = station.strip()
    if len(station) == 4 and station.startswith("K"):
        return station[1:]
    if len(station) == 3 and not textprod.source.startswith("K"):
        return textprod.source[0] + station
    return station