37 C.F.R. § 260.7 Unknown copyright owners.
Title 37 - Patents, Trademarks, and Copyrights
If the designated collecting agent is unable to identify or locate a copyright owner who is entitled to receive a royalty payment under this part, the collecting agent shall retain the required payment in a segregated trust account for a period of three years from the date of payment. No claim to such payment shall be valid after the expiration of the three-year period. After the expiration of this period, the collecting agent may use the unclaimed funds to offset any costs deductible under 17 U.S.C. 114(g)(3). [63 FR 25413, May 8, 1998, as amended at 64 FR 36576, July 7, 1999; 68 FR 36470, June 18, 2003; 68 FR 39841, July 3, 2003; 68 FR 57815, Oct. 7, 2003]
Title 37: Patents, Trademarks, and Copyrights
PART 260—RATES AND TERMS FOR PREEXISTING SUBSCRIPTION SERVICES' DIGITAL TRANSMISSIONS OF SOUND RECORDINGS AND MAKING OF EPHEMERAL PHONORECORDS
§ 260.7 Unknown copyright owners.

