There is little guidance on what this category includes, however. Two recent decisions illustrate the difficulties. In Ellis Don Corporation v. Ontario Metal Workers’, 2013 ONSC 5808, Molloy J. held that a decision by the Ontario Labour Relations Board on the admission of evidence fell into the category.
The issue was whether a photocopy of a very old agreement could be considered by the Board. The Board held it could, but because the standard of correctness applied, the Divisional Court could substitute its judgement for that of the Board:
 In this case, the Unions argued that the Board has a statutory power under s. 48(12)(f) and s. 111(2)(e) of the Labour Relations Act to accept such oral or written evidence as it, in its discretion considers proper, whether admissible in a court of law or not. I do not disagree that if the Vice-Chair had rested his decision on findings of fact and his discretion to admit evidence under the provisions of the home statute, a reasonableness standard might well be appropriate.
In the event, Molloy J. held, the Board got it wrong. Its decision was quashed. However, the Vice-Chair did not rely on this provision of the Act. Rather, he found the document to be admissible under the common law principle relating to ancient documents and as a business record under s. 35 of the Evidence Act. These are questions of law of general application outside the special expertise of this tribunal. Further, they are issues of central importance to the administration of justice. Decision-making on matters of principle such as this should be consistent. In my view, the Vice-Chair was required to be correct as to the application of these general legal principles.
The result may seem slightly surprising. After all, matters going to the admissibility of evidence are matters on which one would expect a deferential approach to be appropriate. This would be so even in the absence of the provisions of the Labour Relations Act identified by Molloy J., but these provisions strongly suggest that the Board was interpreting its home statute, a category of interpretive decisions to which a standard of reasonableness undoubtedly applies. As Hourigan J. noted in his concurring reasons:
 With respect to the standard of review, I find that the reasonableness standard applies. In this case the Board was dealing with a determination of an issue that goes to the very essence of its expertise, being the existence of collective bargaining rights in the construction industry. Moreover, the admission of the evidence, as will be described below, is governed by specific provisions of the Labour Relation Act, 1995, S.O. 1995, c.1, which grant the Board broad power to admit evidence. In any event, even if a correctness standard applied, I find no error in law..
That the characterization of a decision as a question of general law of central importance to the legal system is not straightforward is demonstrated by another recent decision: Walchuk v. Canada (Justice), 2013 FC 958. Here, the applicant had applied for ministerial review of his conviction for second-degree murder. This was refused, because inter alia: I concede that the Vice-Chair’s conclusions that the document was admissible pursuant to the business records exception and the ancient document doctrine were not correct. But admissibility pursuant to either ground was not necessary given his statutory power. Moreover, read purposively, the Vice-Chair’s analysis in this regard is really nothing more than a determination that the reliability and authenticity of the documents had been proven to his satisfaction. This purposive analysis of his reasons is entirely consistent with the principle of deference and does not cross the line to a re-writing of the Vice-Chair’s decision.
Even assuming that the fire that killed the victim was not started by an accelerant, I am of the view that there is compelling evidence remaining that Mr. Walchuk intended to kill the victim based on the following…I am of the view that based on the trial judge’s findings, these new reports-whether considered alone or together-would not have impacted the trial judge’s decision to convict in any event
Manson J. applied a standard of reasonableness to this decision, despite the applicant's plausible argument that the interpretation of "miscarriage of justice" was a question of general law of central importance to the legal system:
Of course, the reasonableness standard that applies to interpretations of law is quite intrusive. Here, the Minister's decision was upheld on the basis that it accorded with a dictionary definition and legislative history. Notwithstanding the persuasive and well-argued position of the Applicant’s counsel that I should deviate from the decisions in Thatcher, Bilodeau (2009), Bilodeau (2011), McArthur, and Daoulov, I must decline to do so. In my opinion, the standard of review is satisfactorily established on the basis of this jurisprudence and the Supreme Court’s recent decision in Agraira. In Agraira, the Court addressed the exercise of ministerial discretion in a context which required the concurrent interpretation of the term “national interest.” In so doing, the court rejected the bifurcated standard of review proposed by the Federal Court of Appeal and applied the reasonableness standard to both the exercise of discretion and the interpretation of the term “national interest.” While the term “national interest” involves different considerations than those underlying the interpretation of the term “miscarriage of justice,” I am satisfied that Agraira, when read with the other jurisprudence cited by the Respondent, is determinative that the reasonableness standard of review applies in the instant application.