43 CFR §5424.1

1. (a)To determine whether substitution has occurred, the authorized officer may require that information identified in the contract be reported by:
   1. (1)A purchaser who has exported private timber within two years preceding the purchase date of Federal timber; and/or
   2. (2)An affiliate of a timber purchaser who exported private timber within two years before the acquisition of Federal timber from the purchaser.
2. (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.