You can now embed videos in your forum posts!
Take a look at the source of this post to see what the bbcode looks like; there's a "flash" button to the left of the "insert image" button.
Spoiler
https://www.youtube.com/watch?v=qo6qIvo9YOw
Edit (7/28/19): with the updated plugin, all you need to do is paste the video URL into the post, no need for any markup.
Videos from YouTube, Vimeo, and Google Video should work.
The same rules that apply to images apply to videos as well; so don't go too crazy :)
Spoiler
http://www.youtube.com/watch?v=isOy9C590rc
Thought this would be a fitting video to try it with. Might as well be my first post too. Long time starsector player and forum lurker, hiding in the shadows and behind nebulas, always out of sensor reach...