Inclusion in returns: Any person required under the authority of this title to make a return, statement, or other document shall include in such return, statement, or other document such identifying number as may be prescribed for securing proper identification of such person. Furnishing number to other persons: Any person with respect to whom a return, statement, or other document is required under the authority of this title to be made by another person or whose identifying number is required to be shown on a return of another person shall furnish to such other person such identifying number as may be prescribed for securing his proper identification.[23]