An external cast is a separate file that must be explicitly linked to a movie for the movie to use its cast members.
If you link an external cast to a movie, Director opens the cast every time it opens the movie. If you don't link an external cast to a movie, you must open and save the file separately. You can use unlinked external casts as libraries to store commonly used elements for authoring, such as scripts, buttons, and so on. For more information, see Creating libraries.
When you distribute a movie that uses an external cast, you must include the external cast file. For disk-based movies, the cast must be in the same relative path in your files as it was when the movie was created. For Shockwave movies on the web, the cast must be at the specified URL.
If you don't want to use the cast in the current movie, deselect the Use in Current Movie option.
The cast is created, and a Cast window for the cast appears in List view. For more information, see Using the Cast window.
You can link to casts on your local disk or to casts that are stored at any URL. Click Internet and enter a URL (in the Find URL text box) for a linked external cast. Click OK.
Note: To use a cast member from an external cast without creating a link to the external cast, first copy the cast member to an internal cast or to a (different) linked external cast.