The literature makes frequent reference to the dangers of accepting photocopies of documents at face value without a searching evaluation. The proponent of the document will try to have everything correct on his master prior to the photocopying and subsequent destruction of the master. The proponent of a document must invariably “take a position” when questioned about the preparation and location of the alleged original of a document. Date-of-introduction (DOI) files exist on the introduction of mechanical devices such as typewriters and photocopy machines although there may be difficulties in differentiating the specific makes and models of machines. In any case, where there is one clear-cut incompatibility with the correct general DOIs and specific DOIs, basis exists to claim that the document cannot be authentic. Naturally, correct, authenticated DOIs must be used.