This function identifies the specified device driver as a valid CD-ROM driver. File system drivers (FSDs) and applications should call this routine before issuing IOCtls that could lead to confusion or data damage if received by a non-CD-ROM driver. This function is performed regardless of whether the drive is already playing.
Note: Any two valid ASCII digits, each in the range of hex 30 to 39, can be used after the "CD" to indicate the caller wanting to identify the CD-ROM driver.