(1) For special provisions relating to foreign corporations carrying on an insurance business within the United States, see section 842.

(2) For rules applicable in determining whether any foreign corporation is engaged in trade or business within the United States, see section 864 (b).

(3) For adjustment of tax in case of corporations of certain foreign countries, see section 896.

(4) For allowance of credit against the tax in case of a foreign corporation having income effectively connected with the conduct of a trade or business within the United States, see section 906.

(5) For withholding at source of tax on income of foreign corporations, see section 1442.