Your just gonna have to make 2 directories one for private .Onions and one for .Onions who people post all over the net trying to direct people to. I don't think you can handle both without 2 seperate directories.
Create a public directory and keep the same .Onion system in place now if possible where someone can give their long string .Onion and either post or it keep it private. That seems like the best way to go, but people will want assurance that the public directory is not tampered with...............
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