There are U.S. Standards for Persian limes U.S.No.1, U.S. Combination and U.S. No.2 grades U.S. No.1 consist of Persian Limes which are firm, fairly well formed, fairly smooth texture, which are free from decay, stylar end, breakdown, or other internal discoloration, broken skins which are not healed, bruises, hard or dry skins, and free from damage caused by freezing, dryness, or mushy condition, sprayburn, exanthema, scars, thorn scratches, scale, sunburn, scab, blanching, yellow color, discoloration, buckskin, dirt or other foreign material, disease, insects or mechanical or other means.