QuickTime Pro enables content creators to export movie files in 3GPP formats that can be played on mobile devices. If you export a movie in the Mobile MP4 3GPP format, it's important to note that only certain annotation fields will be present in the resulting movie.
Supported Annotation Fields:
For example, if your source movie contains annotations for Comment, Title and Description, the resulting 3GPP Mobile MP4 format movie will only contain the Title and Description annotations.
More information about QuickTime, 3GPP, and other mobile formats is available from the QuickTime Mobile Technologies page.