The board's BB Code only supports YouTube videos which uses the YOUTUBE tags which you can find in the BB Code Guide by
CLICKING HERE.
The following tutorial on YouTube is for another forum using phpBB but it works similarly as to how we have set it up here in Invision Powerboard other than we do not have a button on the editor interface to automatically insert the YouTube tags:
The code example for the above video was entered as follows:
CODE
[youtube]4-iI6UnKUCs[/youtube]
Hope that helps!