Type for 708 caption service number (A/65B 6.9.3 caption_service_number) Used to indicate the presence of 608 line 21 analog captions Describes a 708 DTVCC digital captions service 708 captions service number Language of the caption service Indicates the aspect ratio for which the caption service has been formatted Indicates if the caption service is formatted for beginner readers. Caption Service Descriptor (A/65B 6.9.3) Means that there is no caption service Indicates that analog captions are present Describe digital captions services