31 C.F.R. § 588.306
Interest
Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct or indirect.
Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct or indirect.