This is a sandbox project, which contains experimental code for developer use only.
With Post anonymously module you can post anonymously nodes and by having the right permissions. Once you post anonymously other users may not see your ursername because of this awesome module.
Imagine that you are very popular in a Forum XYZ. And you've just seen a movie that you didn't like and you want to create a forum topic cursing about that movie. But you do not want that other users see your posts. But if Post anonymously module is enabled and the proper permissions are configured correctly, you may check a button which says "Post anonymously". And you will see that your post is anonymous. And people will not see your username in the forum topic.