It is a very interesting stamp. It makes me think the designer didn't want to give any country advantage or disadvantage by adding resp. not adding the peticular flags. So I was wondering if all flags belong to not-existing countries, or might there be a 'real' flag, too?
I didn't even notice that. I don't see a real flag, just some that look like they might be familiar.
How cool! I'm envious. I've always wanted to receive one from the UN HQ in Vienna but no luck until now.
I have only received mail from the NY UN.
The UN has to be seen not to favour one country in front of another. At first sight I cannot identify any of the flags.
It's a clever, inclusive design.