Hi Andy,

OrangeCD only uses CD's table of contents (TOC) to identify the disk. No other information (such as serial number, CD-TEXT, etc.) is used for that purpose.

Simply speaking, the TOC consists of numbers which represent the durations of each track in 1/75 sec units. Therefore, it does not matter if some of the tracks do not contain audio information - the TOC of the mixed mode CD can be used to identify the disc as well as normal audio CD.

Andrei