What are the treatment methods of coffee beans G1 G2 G3 G4 respectively?

In fact, these Grade-2,Grade-3 do not exactly represent the level of quality. What does that mean? As follows: washing: Grade-1;Grade- 2 days sun: Grade-3;Grade-4;Grade-5 and Grade-1 several points to note: a) regardless of washing and sunlight, there is Gr-1, the condition is "zero" defect and Premium Cup. Whether it's washing or tanning, Gr-1 rates the boutique of the boutique or Cup of Excellence coffee. B) the lowest level of sun-tanned Shifei and Sidamo is Gr-4. C) beans of the same level, such as Lim gr-2, have both good and bad, depending on the sorting level and input of the exporter. D) to meet the requirements of existing "zero" defects, gr-1 beans (including those washed in water or in the sun) are extremely rare because of the high cost of processing and very few suppliers will do them.