Yes, you've seen this in Wikipedia; the fake MediaWiki interface. Want it? Read it.

To create one Edit

First, you'll need to start with the div syntax:


Next, choose class="usermessage".

<div class="usermessage">

Now, enter your text. We'll go with the one above:

<div class="usermessage">You have [[User:Blow of Light/Played!|new messages]] ([[User:Blow of Light/Played!|Last change]])

Finally, end the message with </div>

Then, if you get it right, you'll get the message above:

Wikia Edit

On Wikia, you'll find more bizarre headers, like this:

You have new messages on Projectname