Do Not Reduce (DNR) is an order qualifier for an order placed under the market that stipulates that the price of the order is not to be reduced for the distribution of ordinary dividends.
Applying "Do Not Reduce (DNR)" to Securities Exams:
When an order is placed underneath the current market price on a good til cancel basis that order will ordinarily be reduced when the stock trades ex dividend. this is done so that the order underneath the market is not executed simply because the stock price is adjusted down when the stock trades ex dividend. If the investor does not want the order to be reduced the order will be marked do not reduce or DNR.