def preamble_for_label(label):
    """
    Return the preamble for the documentation block for the given label.

    :param label: The label to use as the paragraph title.
    :return: The string that should be preamble of the new section.
    """
    preamble = str("\n" + " "*4 + "@par " + label + ":\n\n")
    preamble += str(" "*4 + "@htmlonly\n\n")
    return preamble