Table 255

+===========-===========================================================+ 
|  ADR code |  Description                                              | 
|-----------+-----------------------------------------------------------| 
|     0h    |  Sub-channel Q mode information not supplied              | 
|     1h    |  Sub-channel Q encodes current position data              | 
|           |  (i.e. track, index, absolute address, relative address)  | 
|     2h    |  Sub-channel Q encodes media catalogue number             | 
|     3h    |  Sub-channel Q encodes ISRC                               | 
|  4h - Fh  |  Reserved                                                 | 
+=======================================================================+