3. In relation to postal stationery, the reference to number in paragraph 2 shall be construed as a reference to the number of sheets of paper, cards or envelopes, as the case may be, in the pad, confining band or other form of container; and postal stationery shall be exempted from the requirements of that paragraph if pre-packed as part of a collection of articles made up for sale together and including any article other than postal stationery and blotting or other paper.N.I.