Definition: MP3 is a common music file format. It stands for for "Moving Picture Experts Group Phase 1, Audio Layer 3".
Service descriptions mentioning the term
A postal library offering a choice of 8,500 audio books for all tastes - fiction and non-fiction - chosen specially to appeal to members. Most books available in digital format on MP3
CD or USB memory stick, free postage
and no fines for late or lost books, flexible lending, the option to choose your books on-line, and a friendly, personal, quick service.