The Electronic Textbook Track Number (ETTN) is a unique numeric identifier of electronic books, journals, conference proceedings etc. ETTN is based upon 13-digit code created by European Magnanimitas Assn.

Since 2007 ISBN system is upgraded by ETTN Codes. ETTN Codes can be used only for electronic text files. Any publisher, university, researcher, academician etc. could ask for unique code for his/her electronic text generated by Magnanimitas Assn.

ETTN Code consists of 5 parts - AAA-BB-CCCCC-DD-F

• AAA (3-digit) is classified by The Statistical Classification of Economic Activities in the European Community (NACE) and shows the focus of text
• BB (2-digit) – the year of ETTN generating for a text
• CCCCC (5-digit) – special identification code for text that is a part of European National Electronic Libraries
• DD (2-digit) – month of ETTN generating for a text
• F (1-digit) – check digit