At any point, if you are in doubt about any aspect of how to evaluate a defect or how to interpret the defect portion of a specification, ask your Team Leader.
So what is a defect? How do we grade them? The USDA standards are used as a guideline for which we grade the various types of defects according to size and color.
The tolerances which are set are based on the customer's view and the extent the defect level may reach before they seriously detract from the appearance of the product and also reflects the plant's capabilities to produce to these levels.