The Central Board of Direct Taxes (CBDT) has issued Notification No. 39/2023, dated 12-06-2023, which notifies the Cost Inflation Index (CII) as '348' for the Financial Year 2023-24. The CII is used to calculate the indexed cost of acquisition when a long-term capital asset is sold. This indexed cost of acquisition is deducted from the capital gains instead of just the original cost of acquisition. The purpose of applying the Cost Inflation Index is to account for the impact of inflation and adjust the cost accordingly.