Adding tags to our component
The major new feature introduced in Joomla! 3.1 is the tagging component, which can also be integrated with third-party components. Tags are a kind of metadata that allow you to assign a keyword or multiple keywords to an item, and are popular with blogging sites. They also solve the problem of assigning articles and other contents to multiple categories.
At the time of writing, I am using Joomla! 3.1.1; however, the documentation for tags indicates that there will be some changes made in 3.1.2, so I recommend you refer to http://docs.joomla.org/Using_Tags_in_an_Extension for the latest documentation. Another useful reference is https://github.com/elinw/joomla-cms/wiki/Using-tags-in-an-extension.
The first thing we want ...