• It may work provisionally, as when a tribunal refuses to consider one kind of evidence until another kind (presumably better) is shown to be unavailable, or it may work absolutely, as when the tribunal refuses to consider anything but the better kind of evidence. [Cases: Criminal Law 398. C.J.S. Criminal Law §§ 833–836, 843–844.]
preferential rule
Evidence. A rule that prefers one kind of evidence to another.