20. The Scottish Ministers shall not be obliged by virtue of paragraph 14 or 18 to serve upon any person more than one copy of the same document; and where any person has confirmed in writing to the Scottish Ministers that they do not wish to be served with a copy of, or a copy of any part of, a document that the Scottish Ministers are required to serve on that person by virtue of those paragraphs, the Scottish Ministers shall not be required to serve upon that person that document or the relevant part of it.