The shoutbox is the place where you can leave article-related comments and it is shown below each article in the wiki. You want to hide the shoutbox? No problem. If you don´t want to provide this comment functionality at a certain article, just insert __NOSHOUTBOX__ in the wiki code of the article (it doesn´t make a difference if you add it on top or bottom of your code). Save the changes and the shoutbox won´t be shown at this article.
For administrators: You can also hide the shoutbox globally, so it won´t be shown in any case. Go to the admin preferences and open the tab “Shoutbox” in the “BlueSpice – MediaWiki settings”. You can also do some configuration here. Take a look at it!
And if you are an expert for the rights management, you can also have a look at the shoutbox rights “readshoutbox” and “writeshoutbox”.