Has anyone used this successfully or found further documentation than just the below (from the Adobe site):

frames.frame label class_name [...]

Specifies a SWF file frame label with a sequence of class names that are linked onto the frame.

This option lets you add asset factories that stream in after the application that then publish their interfaces with the ModuleManager class. The advantage to doing this is that the application starts faster than it would have if the assets had been included in the code, but does not require moving the assets to an external SWF file.

This is an advanced option.