Section 17(7) in The Indian Post Office Rules, 1933
(7)Documents wholly or partly produced in imitation of printing as well as documents reproduced from printed manuscript or typewritten originals by photocopying or any similar process;Provided that:-(i)At least 20 identical copies of such documents are presented for posting at the post office counter;(ii)If such documents are posted in letter boxes, they will be treated as letters;
