Section B of the S Corporation Shareholder Stock and Debt Basis Limitations form is used to report adjustments to the debt basis of the shareholder. Debt basis refers to the shareholder's adjusted basis in the debt of the corporation. Adjustments may include changes due to loan repayments, loan forgiveness, or the issuance of additional debt. These adjustments are necessary to accurately calculate the shareholder's gain or loss on the repayment of the loan.