It should be the post box number of the agent that processed DV application. Agents force/ask the DV applicants to use their address convincing them that other addresses may not be reliable, post office does not deliver to other addresses or whatever...depending on how dumb the applicant is. Benefit: the agent's address gets the letters of several DV applicants, and the agent then asks for heavy amount to further process them. The winners are now stuck, can't move forward without the mercy of the agent.