Creating users... question about Nickname and Public Profile

When creating a user in backend, there is a Nickname textbox.  Where does this value get used, by default?  Widgets?  Other places? 

Also, what does the checkbox "is a public profile" do?

I searched but couldn't find information in documentation.

Hello Marko,

By default, the Nickname is the same as the Username. It will be used in the Forums module when showing who's created/replied to a thread. Users with "Is a public profile" get a link from the forum to a public user profile page. I'm not sure where else these properties are being used, if anywhere.