985.0.3. For the purposes of this Book, the geographical boundaries of a municipal or public body performing a function of government in Canada are(a) the geographical boundaries that encompass the area in respect of which a law of Canada or an agreement given effect by a law of Canada recognizes or grants to the body a power to impose taxes; or
(b) if paragraph a does not apply, the geographical boundaries within which that body is authorized by the laws of Canada or of a province to exercise that function.