Volume A focuses on international tax law materials. On the basis of the 2017 version of the OECD Model Convention comparisons are included with the 1963 OECD Draft Convention, the 2017 UN Model and the 2016 US Model. The OECD Model itself, the introduction to this Model and the OECD Commentary are presented in a way in which the successive changes, additions and deletions that were made to the 1977 text in 1992, 1994, 1995, 1997, 2000, 2003, 2005, 2008, 2010, 2014 and 2017 can be readily identified.

The new edition comprises also a fully edited version of the 2017 UN Model along with the much expanded 2017 Commentary on this Model, highlighting not only the comprehensive changes and additions made to the earlier versions of the UN Commentary but also marking the extensive inclusions of sections from the OECD Commentary.