Data (D): This bit is 1 for data sectors related to the program.
                    Will be set.
                    When this bit is 1, the Form bit must be 0.
Audio (A): 1 is set for the audio sector.
                    ∙ When this bit is 1, Form bit is also set to 1.
Video (V): 1 is set for the video sector.
End Of Record (EOR): Set to 1 at the last sector of a logical record. 

In all sectors except for the empty sector, only one of bits 1, 2, and 3 (Video, Audio, Data) must be set to 1.

(4) Coding information

The coding information byte defines the details of the sector data type.
* Not specified in GAME-CD.

Empty sector information
∙ A sector whose channel number and coding information are 0 and all bits of sub-mode Data, Audio and Video are 0.
The empty sector is required to be a Form2 sector with all user data areas set to 0.