The HTML5 <footer> tag is necessary for adding a footer for a particular document which serves as supplementary reference. Just like in other forms of document, the HTML5 <footer> tag is supposed to contain additional details like information about the author, contact details, copyright details or links which can be clicked to go to the terms of use page.

Typically, the HTML5 <footer> tag is used at the bottom of the document. However, the use of HTML5 <footer> tag is not just limited to that. It is also acceptable to use the HTML5 <footer> tag more than once in a single document.

The HTML5 <footer> tag is incorporated in the document, this is how it should appear:

<footer>Copyright 2011-2012.</footer>

It has to be noted though that when contact information is placed within the HTML5 <footer> tag, the use of HTML5 <address> tag is necessary to be able to differentiate it from other texts.

The HTML5 <footer> tag is not seen in HTML4.01. The best thing is that major browsers do no have issues in recognizing HTML5 <footer> tag. The HTML5 <footer> tag is also supportive of both the Global Attributes and Events Attributes.