Tax exemption approval guidelines require timely application, staged infrastructure investment, and accountant certification for public companies. Board approval for the specified tax exemption provisions depends on a public company's timely application in Form No. 59, supporting incorporation and financial documents, staged investment of raised capital in infrastructure facility, and filing of an accountant's certificate showing yearly investment. The Board must issue a written order granting or refusing approval after hearing the company before refusal, and may withdraw approval for failure to invest as required or to file the certificate.