def find_attribute(rcv, xpath, attribute_name):
    """Find an attribute in the RCV record which can have either zero or one occurrence. Return a textual representation
    of the attribute, including special representations for the case of zero or multiple, constructed using the
    attribute_name parameter."""

    attributes = rcv.findall(xpath)
    if len(attributes) == 0:
        return '{} missing'.format(attribute_name)
    elif len(attributes) == 1:
        return attributes[0].text
    else:
        return '{} multiple'.format(attribute_name)