Grades and Requirements for Head Lettuce Application 155. The grades and requirements set out in sections 156 to 159 apply to lettuce varieties grown from Lactuca sativa var. capitata, Iceberg type. Grades and Grade Names 156. The grades and grade names for head lettuce are Canada No. 1 and Canada No. 2. Requirements for All Grades 157. In addition to the requirements for each grade and subject to the general tolerances set out in section 160, head lettuce of all grades must • (a) be p...