A YouTube video can be posted on the forum so viewers can see it right there. It doesn't have to be just a link.
Instructions: Go to the YouTube video you want and copy the http address. On the "New Topic" or "Full Reply" screen, put your cursor in the message post box where you want the video to appear. Click on the Media Icon button as shown below. Choose "You Tube Video" Paste the YouTube http address in the box and click the OK button to submit it. The video should appear where you inserted it. It may not show in the "Preview" mode, depending on your device.
Some users may not see the embedded video because of software non-compatibility on their device. So also post the You Tube link in your message so everyone can see the video (like this example): https://www.youtube.com/watch?v=-UtMtl5pxZM
Copy the You Tube http address
Click the media button and choose You Tube Video
Paste the http address in the pop-up form to embed the video