OBS_VALUE: Upon the request from other telecom service operators, a common telecommunications business operator may provide technological information or users' personal information needed for the provision of equipment and facilities, wholesale services, interconnection services, joint-use services, billing and collections, and telephone number information services, by concluding a contract with the telecommunications business operator.Provision of information is mandatory if a common telecommunications business operators belongs to the following categories:1. possessing equipment and facilities indispensable for other telecommunications business operator to provide telecommunications services;2. its business scale, market share, etc. of common telecommunications services meet the standards prescribed by Presidential Decree (i.e., its market share equaled to or was greater than 50% in the previous year).