Thanks for the explanation! Now I'm confused only with MD5 hash. May be it's better to generate unique names for every user who use this function like Guest 1, Guest 2, Guest 3 e.t.c.? It would be much easier for other users to distinguish different guests in one topic. I don't think, it would require additional SQL load, because User instance, if I'm not mistaken, would include new column automatically.
My idea is that neither users, nor admin don't have to think about hashes and internal mechanism of the plugin.
Thank you!