Because the DAC profile was designed to be a superset of the other known rights information standards, there should be no problem in representing the four rights information standards with the DAC profile. However, due to different expressiveness coverage of the other rights information standards, the reverse directional interoperability between the DAC profile and the other standards seems problematic. Moreover, the interoperability between the other rights information standards except for the DAC profile seems to be even more difficult to achieve in spite of potential needs from the digital home environment. Therefore, further study is required to support the possible bidirectional interoperability between the existing rights information standards as well as reverse directional interoperability between the DAC profile and other rights information standards.