What is the evidentiary threshold established by a court under s. 1 of the Charter?

Raising the Charter implies that an evidentiary threshold must be established by any applicant before a court embarks on a legal analysis. I strongly disagree with the applicant's submission that evidence as to the history and traditions behind the decorum that participants at courts martial in Canada, or in countries with similar traditions and values with regard to the wearing of a military uniform, would not be relevant. That evidence is not required only for the purposes of determining the validity of that provision or situation under s. 1 of the Charter. As stated by Cory, J. in MacKay v. Manitoba, 1989 CanLII 26 (SCC), [1989] 2 S.C.R. 357, at paragraph 9: "Charter decisions should not and must not be made in a factual vacuum."