If you specify a video clip with the dynsrc attribute, the start property controls the action that causes the clip to start running.

Provides the URL of the map element in the same document that contains client-side image map hot areas and links. The value includes the hashmark

The vspace property of IMG is described in chapter: javascript IMG hspace, vspace

Provide the horizontal and vertical pixel coordinates of the top-left corner of the image relative to the page. These are Navigator-only properties,