When nothing will do but a video in your mark you can use the same technique as with embedding audio by using the source mode of the WYSIWYG editor. In this case you may want to use a service like YouTube.com to host your video. If you just want to use a video already on YouTube go to the video's page and copy the text they supply in the "embed" box. Then paste it into your mark. It will look something like this:

<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/ROXTq5Z914w"></param><embed src="http://www.youtube.com/v/ROXTq5Z914w" type="application/x-shockwave-flash" width="425" height="350"></embed></object>

The actual snippet of code you get from YouTube.com contains a property setting wmode="transparent". This is not supported in marks so you will have to remove it as we did in the example above. Several other Flash based applications including the odeo.com audio player use this parameter too and it will therefore have to be removed from their snippets too. If you would rather use the standard media player and you know the address of the video you want to use you can put the following much simplified tag in your mark:

<embed src="URL-to-your-video-file">