What are PQ and ISRC?

The PQ is the data that creates the flags to mark the start and end of each track and the Table of Contents on the CD.

ISRC is the International Standard Recording Code which is a unique identifier for every track ever released.

To find out more about ISRCs and where and how to register go to http://www.ifpi.org/isrc/ where you will find details of all the different agencies worldwide.