Practice Pointer. Having a Virtual Asset Instruction Letter (VAIL) can help control what happens to virtual or digital assets should the owner pass away or become incapacitated. Account names and numbers, passwords, answers to security questions and user names are all needed to gain access. A power of attorney for those incapacitated, or a will for those who pass away, can address these issues. This is an important component for the continuity of any business should the worst happen.