The variety or type of any lot, of walnuts in the shell may be specified in accordance with the facts as follows:

(a) If the lot is of one named variety, that variety name may be specified, Provided, That not over 10 percent, by count, of the walnuts in the lot are of another variety or type than that specified; and,

(b) If the lot is a mixture of two or more distinct varieties or types it may be specified as “Mixed Varieties”.