Code of Federal Regulations Title 20. Employees' Benefits § 20.404.708 How we decide what is enough evidence

(a) Information contained in the evidence was given by a person in a position to know the facts;

(b) There was any reason to give false information when the evidence was created;

(c) Information contained in the evidence was given under oath, or with witnesses present, or with the knowledge there was a penalty for giving false information;

(d) The evidence was created at the time the event took place or shortly thereafter;

(e) The evidence has been altered or has any erasures on it;  and

(f) Information contained in the evidence agrees with other available evidence, including our records.