Nearly every county of origin has its own grading scale. It can be incredibly confusing. Sometimes the coffee earns a higher grade than it deserves, sometimes the grade is actually lowered to avoid tariffs! Central and South Americans tend to follow the SHB and SHG model (Strictly Hard Bean and Strictly High Grown indicates altitudes above 1000m). So hard beans grow at higher altitude and that's good, right? Well, in Brazil's grading, Strictly Soft is a top grade. Many countries use a simple numeric scale. But a Grade 4 Ethiopian is the top Dry-Processed grade you'll see (Gr.2 in washed Ethiopians), and a Grade 1 Sumatra DP allows 8% defects (in fact Sumatra Grading is based on cup quality)! In essence, all should conform to the Green Coffee Classification System, but they don't. See the SCAA Green Coffee Classification Poster or the Green Coffee Association charts.