(a) The Internal Revenue Code provides in part as follows:
Chapter I—Income Tax
Sec. 22. Gross income.
(b) Exclusions from gross income. The following items shall not be included in gross income and shall be exempt from taxation under this chapter:
(7) Income exempt under treaty. Income of any kind, to the extent required by any treaty obligation of the United States;
Sec. 62. Rules and regulations. The Commissioner, with the approval of the Secretary, shall prescribe and publish all needful rules and regulations for the enforcement of this chapter.
(b) Pursuant to section 62 of the Internal Revenue Code, other provisions of the internal revenue laws, and to Article XXII of the convention, the following regulations, which are designated as §§ 521.101 to 521.117 are hereby prescribed and all regulations inconsistent herewith are modified accordingly.