Crystallization of regular practice & the IRS??
- "[G]overnment is a practical affair, intended for practical men. Both officers, lawmakers, and citizens naturally adjust themselves to any long-continued action of the Executive Department, on the presumption that unauthorized acts would not have been allowed to be so often repeated as to crystallize into a regular practice. That presumption is not reasoning in a circle, but the basis of a wise and quieting rule that, in determining the meaning of a statute or the existence of a power, weight shall be given to the usage itself,-- even when the validity of the practice is the subject of investigation." United States v. Midwest Oil Co., 236 U.S. 459, 472-73, 59 L. Ed. 673, 35 S. Ct. 309 (1915).