The tutorial is on activating WordPress shortcodes functionality in comment’s form so that you can enable your commenters to use some shortcodes (assigned by you) while writing any comments on your website. Shortcode in Comment is a handy plugin for this. The plugin lets enable decide which shortcodes you would like to enable in the comment form.
Install and activate the plugin. After activation visit your admin area Dashboard -> Settings -> Shortcodes in Comments page and type or paste comma separated shortcode names which like to enable in comment’s form. Save your changes and you are done.