def CreateParamList(gridID, PSF, ESF, Eo, No):
    """
    Create a custom parameters list. **Be careful** of your inputs

    :param gridID: string, refer to the list at http://www.standardsforhighways.co.uk/ha/standards/ians/pdfs/ian99.pdf
    :param PSF: float - Projection Scale Factor
    :param ESF: float - Elevation Scale Factor
    :param Eo: float - delta Easting
    :param No: float - delta Northing
    
    :returns: Custom parameters for coordinate conversion
    """
    CSF = PSF*ESF
    return (gridID, PSF, ESF, CSF, 1/CSF, float(Eo), float(No))