Broker-dealers will be required to make monthly reports on short interest in securities that are traded over the counter under regulations adopted by the board of governors of the National Assn. of Securities Dealers. The Washington-based group, which oversees trading in the 5,000 stocks currently included in the NASDAQ system, will then compile and publicize the figures much as the New York and American stock exchanges do. A short sale occurs when someone sells a borrowed security on the hope that its price will fall before the security must be bought back and returned to the lender. Short interest measures the amount of such transactions that have not yet been settled.