When you create a clip using the Colour Source command or create a clip composed of identical frames using the Repeat command, you can use the clip as a virtual source in the timeline. A virtual source is a clip that has no real beginning or end, meaning that you can trim, slip or slide it to any extent. For example, if you insert a colour source clip consisting of 10 frames into the edit sequence, you can trim, slip or slide the clip by any number of frames.

Head and tail information for virtual sources is indicated by an asterisk (*).