Serious damage means any defect which seriously affects the appearance, or the edible or shipping quality of the fruit. Any one of the following defects, or any combination of defects the seriousness of which exceeds the maximum allowed for any one defect, shall be considered as serious damage:

Dryness or mushy condition which extends into all segments more than one-fourth of an inch at the stem end, or more than the equivalent of this amount, by volume, when occurring in other portions of the fruit;

Sprayburn which changes the color to such an extent that the appearance of the fruit is seriously injured or which causes scarring that in the aggregate exceeds the area of a circle one-half inch in diameter;

Exanthema (ammoniation) which occurs as small spots over more than 25 percent of the fruit surface, or as solid scarring (not cracked) or depressions which aggregate more than 10 percent of the fruit surface;

Scars which are dark, rough, or deep and aggregate more than 5 percent of the fruit surface, or scars which are fairly light in color, slightly rough, or of slight depth and aggregate more than 10 percent of the fruit surface, or scars which are light colored, fairly smooth, with no depth and aggregate more than 25 percent of the fruit surface;

Thorn scratches when the injury is not well healed, or when dark colored, rough or deep and aggregates more than 5 percent of the fruit surface, or when light colored, fairly smooth and concentrated and aggregates more than 10 percent of the fruit surface, or light colored and scattered thorn injury which detracts from the appearance of the fruit to a greater extent than the 10 percent light colored concentrated injury;

Scale when the appearance of the fruit is affected to a greater extent than that of a lime which has a blotch the area of a circle one-half inch in diameter;

Sunburn which causes decided flattening of the fruit, marked drying or dark discoloration of the skin, material drying of the flesh underneath the affected area, or which affects more than 10 percent of the fruit surface;

Scab which seriously affects shape or texture;

Blanching when more than 50 percent, in the aggregate, of the fruit surface shows a whitish to yellowish green area or areas because of shading, resting on the surface of the ground, or contact with other fruit on the tree. Such areas are not to be confused with limes which are turning yellow due to the ripening process;

Yellow color when plainly visible and caused by the ripening process;

Discoloration caused by rust mite, melanose or other means, when fairly smooth and more than 50 percent of the fruit surface is affected, or when slightly rough and more than 25 percent of the fruit surface is affected; and,

Buckskin when more unsightly than the maximum discoloration allowed, or the fruit texture is seriously affected.