For each treaty preparatory documents exist. Of only a limited number of treaties, however, these documents are published. When a treaty has been concluded within the framework of an international organization, you should also check the website of that organization. When the International Law Commission has been involved in drafting a convention, you can find reports on the preparatory work in the ILC's Yearbook and on its website . These could contain references to a treaty's travaux pr paratoires.
Commentaries are authoritative explanations of treaty provisions.
For example the Commentary on the Geneva Conventions by Jean Pictet has been published by the ICRC and is also available on the ICRC s internet site. The General Comments of the respective treaty bodies on the Convention on Civil and Political Rights, the Convention on the Elimination of Racial Discrimination and the Convention Against Torture are available in the case law databases of the SIM Documentation Centre . In addition it can be useful to see how national governments and parliaments interpret treaty provisions. References to these can be found in the notification of the Dutch ratification, which is published in the Tractatenblad . You can also find the references by searching the cd-rom Register Offici le Publicaties .