It may be correct to say that the EXCOM Conclusions in general do not legally bind Japan and
the Committee members automatically. However, the EXCOM Conclusions may contain persuasive
logic and rationale on which courts may rely. Moreover, the dynamics of the interaction between any
one conclusion of the EXCOM Conclusions and state practice, and the value of the conclusion as a
means to interpret the Convention should be examined. That is to say, evaluation of the evidential
value of a specific EXCOM conclusion requires investigation of its normative nature. For instance, to
what degree did existing state practices influence the development of the specific resolution? Has the
conclusion been incorporated in the subsequent practice of the state parties to the Convention? Has
the conclusion been firmly observed by the state parties? If so, is it possible to assume that the
particular EXCOM conclusion represents particular rules and standards of a binding nature, or
reflects international custom, and that the various state parties identify various elements of the
Conclusions with which states must comply? The conclusion could have an evidential value in the
application of the Convention in state practice.
The Japanese courts also declined to use other resources which may help interpret the terms of
the Convention. The decision of RQT v Minister of Justice of the Tokyo High Court denied the
necessity of knowledge of the Handbook on Procedures and Criteria for Determining Refugee Status
Under the 1951 Convention and the 1967 Protocol Relating to the Status of Refugees (UNHCR
Handbook). The applicant claimed that the UNHCR Handbook should be consulted under article
32 of the Vienna Convention on the Law of Treaties as a "supplementary means" to interpret the term
refugee and to figure out the appropriate standard of proof for determining refugee status. The Court
rejected the argument on the grounds that the UNHCR Handbook was not a "supplementary means"
in terms of the Vienna Convention on the Law of Treaties. The Court's decision also implied the needlessness of any supplementary means, including the survey of the Convention history, when
interpreting the definition of refugee:
…concerning the term 'refugee' which is stipulated in article 1 of the Refugee Convention and in article 1
of the Refugee Protocol, as it can be interpreted without using supplementary means [provided in the
Vienna Convention]…, it should be said that it is not necessary to confirm the interpretation by resorting
to supplementary means.