Beer may be removed from a brewery for consumption or sale only in barrels, kegs, bottles, and similar containers, as provided in this part. A container which the appropriate TTB officer determines to be similar to a bottle or can will be treated as a bottle for purposes of this part. A container which the appropriate TTB officer determines to be similar to a barrel or keg and which conforms to one of the sizes prescribed for barrels or kegs in Sec. 25.156 will be treated as such for purposes of this part. (Sec. 201, Pub. L. 85-859, 72 Stat. 1389, as amended, 1390, as amended (26 U.S.C. 5412, 5416))