def METHOD_NAME(kernel: int) -> str:
    """
    Convert major XNU version to Marketing name
    Parameters:
        kernel (int): Major XNU version
    Returns:
        str: Marketing name of OS
    """
    try:
        # Find os_data enum name
        os_name = os_data(kernel).name
        # Remove "_" from the string
        os_name = os_name.replace("_", " ")
        # Upper case the first letter of each word
        os_name = os_name.title()
    except ValueError:
        # Handle cases where no enum value exists
        # Pass kernel_to_os() as a substitute for a proper OS name
        os_name = os_conversion.kernel_to_os(kernel)
    return os_name