the IRS contends somewhat obliquely that the district court’s analysis improperly combined an equitable doctrine with the technical elements of a detailed federal statutory scheme. A straightforward consideration of the text, however, puts this argument to rest. Section 6323(h)(1)(A) defines a “security interest” as an interest that is enforceable against subsequent judgment creditors under local law. Maryland’s doctrine of equitable conversion is local law, and it makes Susquehanna Bank’s deed of trust enforceable against subsequent judgment creditors. Nowhere does § 6323(h)(1)(A) limit local law to exclude established principles of state common law. Moreover, federal courts have often invoked equitable principles of state law when applying § 6323(h)(1)(A). See Haas, 31 F.3d at 1091 (<HOLDING>); Regions Bank, 2013 WL 635615, at *2-3 (same);
holding that although alabama state law would give a mortgagee who erroneously recorded a release of a mortgage an equitable right to have the mortgage retroactively reinstated reinstatement would have resulted in relating back the perfection of the mortgage to the original recording date in violation of treas reg  3016323hla2 holding that federal comparative negligence principles prevailed over state comparative negligence principles on the basis that admiralty is not merely a basis of jurisdiction but instead it is a body of substantive principles as well holding that state equitable principles would retroactively reinstate an erroneously released mortgage but that those principles were nonetheless barred by treas reg  301 6323hla2s prohibition against relation back holding that equitable principles apply to child support proceedings holding that the state law violated equal protection principles