paragraph 199 in volume 2, chapter 12, The Compulsory Jurisdiction (Optional Clause)
The place of reciprocity in the system of the compulsory jurisdiction became obscured during the period of the Permanent Court owing to confusion in State practice, in pronouncements of that Court and in the literature. Early on States began including in their acceptances of the compulsory jurisdiction a specific reference to a condition of reciprocity, using different formulations.1 The Permanent Court did not clarify the basis on which reciprocity was required.…