[Code of Federal Regulations] [Title 22, Volume 1] [Revised as of April 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 22CFR51.6] [Page 255] TITLE 22--FOREIGN RELATIONS CHAPTER I--DEPARTMENT OF STATE PART 51_PASSPORTS--Table of Contents Subpart A_General Sec. 51.6 Mutilation and alteration of passports. Any passport which has been materially changed in physical appearance or composition, or which includes unauthorized changes, obliterations, entries or photographs may be invalidated.