The RBI circular harmonizes NPA recognition practices across all lending institutions. It specifies that loan accounts will be classified as SMA0, SMA1, or SMA2 based on the number of days past due between 0-30, 31-60, and 61-90 days respectively. Accounts become NPAs if interest or principal is overdue for more than 90 days. The circular provides clarification on aspects like out of order status, NPA classification if interest is overdue, and upgradation to standard status. Lenders must educate borrowers on these changes by March 31, 2022.