The Supreme Court thus performs a unique function. It can be asked by the Governor-in-Council to hear references considering important questions of law. Such referrals may concern the constitutionality or interpretation of federal or provincial legislation, or the division of powers between federal and provincial spheres of government. Any point of law may be referred in this manner. However, the Court is not often called upon to hear references. References have been used to re-examine criminal convictions that have concerned the country as in the cases of David Milgaard and Steven Truscott.