Oh, simple as that. I thought it was something like <div class="pull-center">. I use some similar things. In case you haven't seen them I'll show them to you:

This aligns the text to the right side:

This lets you write the code you want without spaces:

• html entities:

• backticks which looks like this: <div class="pull-right">text</div>

• Six spaces also works:

  <div>text</div>
  

And to align the text to the left:

There is also pull-left which has some strange behavior:

text

These are particularly effective for image formatting. I've been exploring these things. I'm really glad to have found <center> today. :D