From the Constitution Act, 1982:
The Constitution of Canada is the supreme law of Canada, and any law that is inconsistent with the provisions of the Constitution is, to the extent of the inconsistency, of no force or effect.
From the Constitution Act, 1867:
138. From and after the Union the Use of the Words “Upper Canada” instead of “Ontario,” or “Lower Canada” instead of “Quebec,” in any Deed, Writ, Process, Pleading, Document, Matter, or Thing shall not invalidate the same.
The most fundamental right of Canadians (moreso than any of those bullshit human rights clauses) is the right to refer to Ontario as Upper Canada, in all things you do.