The very first time Extra Vote Plugin is runned in your site, it will create a new database table for your system to store those extra content ratings.

The content_id field will be filled with your article id, and the extra_id field, with the # you write in the {extravote #} code. Extra Vote will work properly as long as you don't repeat that # number in the same article.

The main content rating behaves just like the core, but the {mainvote} code is also there to allow you to display the stars anywhere else inside of your article

Both {extravote #} and {mainvote} features can be disabled in order optimize it in case you just want to use this plugin for your main content rating

Tip: if you add the styles from extravote.css to your template.css, then you can choose not to Call ExtraVote Style in order to lighten your website, too.