there. I want this to appear at the top of every wiki page.

Hi there. I want this to appear at the top of every wiki page.

<h3 style="border: 2px solid red; padding: 5px; margin: 5px; text-align: center;">This is Wiki <span style="color: #993300;">ANYONE MAY EDIT THIS TEXT</span> you need to register first</h3>

Is this easily achieved. Thanks