(a) To determine whether substitution has occurred, the authorized officer may require that information identified in the contract be reported by:

(1) A purchaser who has exported private timber within two years preceding the purchase date of Federal timber; and/or

(2) An affiliate of a timber purchaser who exported private timber within two years before the acquisition of Federal timber from the purchaser.

(b) Purchasers or affiliates of purchasers shall retain a record of Federal timber acquisitions and private timber exports for three years from the date the activity occurred.