(a) The grade of a lot of filberts shall be determined on the basis of a composite sample drawn from containers in various locations in the lot. However, any container or group of cantainers in which the filberts are obviously of a quality, type or size materially different from that in the majority of containers shall be considered a separate lot, and shall be sampled separately.

(b) In grading the sample, each filbert shall be examined for defects of the shell before being cracked for kernel examination. A filbert shall be classed as only one defective nut even though it may be defective externally and internally.