29 CFR §18.901

1. (a)General provision. The requirement of authentication or identification as a condition precedent to admissibility is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims.
2. (b)Illustrations. By way of illustration only, and not by way of limitation, the following are examples of authentication or identification conforming with the requirements of this rule:
   1. (1)Testimony of witness with knowledge. Testimony that a matter is what it is claimed to be.
   2. (2)Nonexpert opinion on handwriting. Nonexpert opinion as to the genuineness of handwriting, based upon familiarity not acquired for purposes of litigation.
   3. (3)Comparison by judge or expert witness. Comparison by the judge as trier of fact or by expert witnesses with specimens which have been authenticated.
   4. (4)Distinctive characteristics and the like. Appearance, contents, substance, internal patterns, or other distinctive characteristics, taken in conjunction with circumstances.
   5. (5)Voice identification. Identification of a voice, whether heard firsthand or through mechanical or electronic transmission or recording, by opinion based upon hearing the voice at any time under circumstances connecting it with the alleged speaker.
   6. (6)Telephone conversations. Telephone conversations, by evidence that a call was made to the number assigned at the time by the telephone company to a particular person or business, if—
      1. (i)In the case of a person, circumstances, including self-identification, show the person answering to be the one called, or
      2. (ii)In the case of a business, the call was made to a place of business and the conversation related to business reasonably transacted over the telephone.
   7. (7)Public records or reports. Evidence that a writing authorized by law to be recorded or filed and in fact recorded or filed in a public office, or a purported public record, report, statement, or data compilation, in any form, is from the public office where items of this nature are kept.
   8. (8)Ancient documents or data compilation. Evidence that a document or data compilation, in any form,
      1. (i)Is in such condition as to create no suspicion concerning its authenticity,
      2. (ii)Was in a place where it, if authentic, would likely be, and
      3. (iii)Has been in existence 20 years or more at the time it is offered.
   9. (9)Process or system. Evidence describing a process or system used to produce a result and showing that the process or system produces an accurate result.
   10. (10)Methods provided by statute or rule. Any method of authentication or identification provided by Act of Congress, or by rule or regulation prescribed by the administrative agency pursuant to statutory authority, or pursuant to executive order.