Before the adoption of rule of general applicability or the commencement of hearing on such a proposed rulemaking, the Commission will cause general notice to be given by publication in the Federal Register, such notice to be published therein not less than 15 days prior to the date fixed for the consideration of the adoption of a proposed rule or rules or for the commencement of the hearing, if any, on the proposed rulemaking, except where a shorter period is reasonable and good cause exists therefor; Provided however, That:

(a) When the Commission, for good cause, finds it impracticable, unnecessary, or contrary to the public interest to give such notice, it may proceed with the adoption of rules without notice by incorporating therein a finding to such effect and a concise statement of the reasons therefor;

(b) Except when notice or hearing is required by statute, the Commission may issue at any time rules of organization, procedure or practice, or interpretative rules, or statements of policy, without notice or public proceedings; and

(c) This section is not to be construed as applicable to the extent that there may be involved any military, naval, or foreign affairs function of the United States, or any matter relating to the Commission's management or personnel, or to United States property, loans, grants, benefits, or contracts.