use simple BBCode in your comments 
atm follow tags available:
[b]bold[/b] 
[i]italic[/i] 
[u]underline[/u] 
[color=color]text[/color] example [color=FF6600]Text[/color]
list 
[ul] 
[li]number 1[/li] 
[li]number 2[/li] 
[li]number 3[/li] 
[/ul]
[url=http://www.google.com]Google[/url] 
[img=http://uri.to.pic][/img] (fix picsize)
(required wp-syntax) 
[code]your code[/code], 
optional with declaration of the language 
[code lang=”csharp”]your sample code[/code] (all available languages from wp-syntax possible)
<h3>Arbitrary section</h3>
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BBComments

antonchanning

This plugin adds support for video and audio shortcodes to wordpress. 
It integrates with the ‘bbPress2 shortcode whitelist’ plugin to provide 
a safe way of enabling BBCode without giving your users access to all 
shortcodes. If installed with the latter the admin will have the option 
of allowing users to use these audio and video bbcodes in their posts.
<pre><code>Youtube Links: 
Video URLS Links: 
Google Video Links: [gvideo]Google Video ID[/gvideo] [googlevideo]Google Video ID[/googlevideo]
Video URLS Links: [video]Youtube, Vimeo or GoogleVideo URLs only[/video]
Freesound audio: [freesound]freesound.org sound ID only[/freesound]
</code></pre>

Video and Audio BBCodes

This plugin adds support for video and audio shortcodes to posts and pages. If you have 'bbPress2 shortcode whitelist' installed, you can al …

BBComments vs Video and Audio BBCodes