Well, at least at my local post-office an officer asked for an ID even tho' I used a nickname. I asked the reason for that, and the post-officer said she just needs me to prove my identity?? What the hell...? I pulled out my drivers license and asked is that enough, am I really Peter Pan? She grunted something and gave me the package. After that the same person hasn't asked for ID. This has happened only with this person, no one else. I'm not sure if she would have given me the package if I wouldn't have showed my drivers license. But I guess she would have to if I'd ask someone else there to teach her how Poste Restante works.I should add that I don't know whether they ask for an id if you use a real person's name, but if you ask in your post office that are there any Poste Restante letters for the pseudonym Mickey Mouse, they don't require you to prove that you actually are Mickey Mouse.