Del. Code tit. 3, § 918

In addition to the district benefits set forth in § 911 hereof of this title, the owner of real property subject to a preservation easement shall be entitled to exemption from taxation for the transfer of any interest in such real property by death otherwise subject to the estate tax under Chapter 15 of Title 30. The Department of Finance shall be entitled to adopt requirements to effectuate the exemption from taxation as provided hereunder.