Any liquidating distribution you receive is not taxable to you until you have recovered the basis of your stock. After the basis of your stock has been reduced to zero, you must report the liquidating distribution as a capital gain. Whether you report the gain as a long-term or short-term capital gain depends on how long you have held the stock.
If it was a partial liquidation, there is nothing to report on your tax return. You adjust the cost basis of your stock or mutual fund by the amount of the partial liquidation shown in Box 8 or Box 9, then when you eventually sell the stock you will use the lowered cost basis as the purchase price of the stock.
If the liquidating distribution shown in Box 8 or 9 is a complete liquidation, then report the amount in Box 8 or 9 on the stock sale screen as a stock sale. For example, if your cost basis in stock in a company is $1,000 and the company is totally liquidated, then if you receive a 1099-DIV with Box 8 showing $400 and you received nothing else from the liquidation, then you would report the stock as a sale on the stock sale screen and report $400 as the sales price and $1,000 as the cost basis in the stock that was completely liquidated.