What is "good cause" and what is its meaning?

In order to determine what is good cause, it is necessary to look at the facts in issue. The process under s. 309 is one of subjectivity no matter how much we would like to see it as one of objectivity. The opening words are: "The Registrar having good cause to believe ...". The use of the adjective "good" is undoubtedly intended to raise the level and quality of the information that one must have before one can act above mere "cause to believe". Black's Law Dictionary (1979), defines "good cause" as: Good cause. Term generally means a substantial reason amounting in law to a legal excuse for failing to perform an act required by law. People v. Gillett, Colo., 629 P.2d 613, 618. Legally sufficient ground or reason. Phrase "good cause" depends upon circumstances of individual case, and finding of its existence lies largely in discretion of officer or court to which decision is committed. Wilson v. Morris, Mo. 369 S.W. 2d 402, 407. It is a relative and highly abstract term, and its meaning must be determined not only by verbal context of statute in which term is employed but also by context of action and procedures involved in type of case presented.