<spine> Element
The <spine> must have at least one item with the attribute linear="yes", which is the default. Any spine item without the linear attribute defaults to linear="yes". Any spine item with the linear="no" attribute will open in its own window. See Nonlinear Content for more information and a link to an example.
Samples
Removed the sentence “If you deliver via iTunes Producer, creating custom samples is not an option at this time.” You can now deliver samples using iTunes Producer.
Assets
HD video source must be tagged as 709 color space.