Dainya Yoga - exchange of signs between the owners of the 6th, 8th, or 12th house and the rulers of any other houses. There are a total of 30 such yogas. They limit success and prosperity, create obstacles and hindrances in endeavors. A person with this yoga in their chart is characterized by foolishness, an unstable mind, and immoral behavior, insults others, and suffers from enemies. Dainya Yoga, however, is not absolute evil. It certainly erects barriers on a person's path to success by the hands of their enemies, and also indicates failures in endeavors. However, a strong and well-aspected yoga allows a person to overcome their opponents and bypass the obstacles that arise.
Shri Govind Swarup Agarwal - "Vedic Astrology"