the Court has to form an as to the person by whom any document was written or signed, the of any person acquainted with the of the person by whom it is supposed to be written or signed that it was or was not written or signed by that person, is a fact.Explanation. - A person is said to be acquainted with the of another person he has seen that person write, or he had received documents purporting to be written by that person in answer to documents written by himself or under his authority and addressed to that person, or , in the ordinary course of business, documents purporting to be written by that person have been habitually submitted to him.IllustrationThe question is, whether a given letter is in the of A, a merchant in London.B is a merchant in Calcutta, who has written letters addressed to A and received letters purporting to be written by him. C is B's clerk, whose duty it was to examine and file B's correspondence. D is B's broker, to whom B habitually submitted the letters purporting to be written by A for the purpose of advising with him thereon.The s of B, C and D on the question whether the letter is in the of A are , though neither B, C nor D ever saw A write.47A. as to [Electronic signature] [Inserted by Act 21 of 2000, Section 92 and Sch.II (w.e.f. 17.10.2000).] where . the court has to form an as to the [electronic signature] [Substituted by the Information Technology (Amendment) Act, 2008, (10 of 2009), Section 52(c)(i), for "Digital Signature"] of any person, the of the Certifying Authority which has issued the [Electronic Signature Certificate] [Substituted by the Information Technology (Amendment) Act, 2008 (10 of 2009), Section 52(c)(ii), for "Digital Signature"] is a fact.]