[Code of Federal Regulations] [Title 18, Volume 1] [Revised as of April 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 18CFR1b.4] [Page 10] TITLE 18--CONSERVATION OF POWER AND WATER RESOURCES CHAPTER I--FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY PART 1b_RULES RELATING TO INVESTIGATIONS--Table of Contents Sec. 1b.4 Types of investigations. Investigations may be formal or preliminary, and public or private.