Unless included in other information required by this chapter, the application shall set forth the name and main office address of all operating subsidiaries of both the acquiring bank holding company and the bank, trust company, national banking association or domestic bank holding company to be acquired. In addition, the application shall set forth the name, office address, and telephone of one or more persons designated by each applicant to be its official representative in connection with the application. All contact between the director's office and the applicant should, except in extraordinary circumstances, be through such representatives.