Section 590.315 - Witnesses(a) The Assistant Secretary or presiding official may require that the direct testimony of witnesses in trial-type hearings be submitted in advance of the hearing and be under oath, and in written form.(b) Witnesses who testify in trial-type hearings shall be under oath or affirmation before being allowed to testify.(c) Witnesses subpoenaed pursuant to § 590.306 shall be paid the same fees and mileage as paid for like services in the District Courts of the United States.(d) Witnesses subpoenaed pursuant to § 590.307 shall be paid the same fees and mileage as paid for like services in the District Court of the United States.54 FR 53531, Dec. 29, 1989; 55 FR 14916, Apr. 19, 1990