Del. Code tit. 30 § 2071
Any term used in this subchapter shall have the same meaning as when used in a comparable context in the Internal Revenue laws of the United States, unless a different meaning is clearly required or unless any provision of this subchapter ascribes a different meaning to such term. References to the Internal Revenue Code shall mean the sections of the Internal Revenue Code as existing on any date on which any expenses subject to credit under this subchapter are taken into account for purposes of Delaware income taxation. However, if those sections of the Internal Revenue Code referenced in this chapter are repealed or terminated, references to the Internal Revenue Code shall mean those sections last having full force and effect. If, after repeal or termination, the Internal Revenue Code sections are revised or reenacted, references herein to Internal Revenue Code sections shall mean those revised or reenacted sections.
30 Del. C. § 2071