An ontology is recognized as the solution for the integration of information systems. The environment of interoperation may involve many players who have agreed to commit to the ontology in order to maintain their system of speech acts and institutional facts in conformance with the coordinated system. When this interoperating community is established, it can generate a large number of institutional facts due to different range of players who can request different facets of information. In this light, however, how those players commit to ontology is still unclear. This paper discusses what sort of requirements that we need to assist how the players commit to the ontology. The approach of this paper is theoretical which is based on the literature of the concepts of speech acts and institutional facts and a case study of the Olympic games. As a result, we have defined several important commit-time requirements to explain situations of players committing to ontology in the context of ontology-based interoperation of information systems.