From http://www.w3schools.com (Copyright Refsnes Data)

HTML 5 <center> tag


Definition and Usage

Centers its enclosed text horizontally.


Differences Between HTML 4.01 and HTML 5

<center> is not supported in HTML 5. Use CSS to align content.


Tips and Notes

Tip: Use CSS styles to center text!


From http://www.w3schools.com (Copyright Refsnes Data)