To avoid common problems when delivering closed captions, read the iTunes Closed Captioning Testing Guide available in Resources and Help.
By June 30, 2015, TV content deliveries for the U.S. iTunes Store must include closed captions. Be aware of the following special cases:
Only currently valid reason codes will be accepted. Without a valid reason code, content without closed captions can no longer be offered on the iTunes Store in the United States, and will be removed on or after June 30, 2015. Be sure that you update your content with valid reason codes before then.
If you’re not sure which of your deliveries has closed captions, you can get a status list in Catalog Reports.
Learn more in the iTunes Package Film Specification and the iTunes Video and Audio Asset Guide in Resources and Help.
Currently TV only supports original version audio and Closed Captioning.
A scratch encode is a low-resolution copy of the video asset that was delivered to iTunes. A scratch encode is usually used by partners to sync closed captions to episodes already delivered to iTunes.
Scratch encodes are available by doing a metadata lookup in Transporter.