- On the youtube page, click the "share" button under the video.
- when that opens... click "embed"
- copy the code that drops down.
- Paste that code here in the compose window where you type your post (the full editor page NOT quick reply)
- Scroll down a little to where you see the "options" and "click to configure posts"
- When that drops down, click the HTML drop down and choose "HTML ON Auto line break mode"
- Click "add reply" at bottom
Congrats... you posted a video!
p.s. This only works for site supporters in most forums.