|  |  | Explanation of Grades | 
    
        |  | A | Outstanding examples of the feature in a European context. | 
    
        |  | B | Excellent examples of the feature, significantly above the threshold for SSSI/ASSI notification but of somewhat lower value than grade A sites. | 
    
        |  | C | Examples of the feature which are of at least national importance (i.e. usually above the threshold for SSSI/ASSI notification on terrestrial sites) but not significantly above this. These features are not the primary reason for SACs being selected. | 
    
        |  | D | Features of below SSSI quality occurring on SACs These are non-qualifying features (“non-significant presence”), indicated by a letter D, but this is not a formal global grade. |