Maintained by various offices, bureaus, individuals, and committees in the Department of State, the Special Files contain a vast amount ofinformation on a variety of foreign policy subjects. Originally, the Special Files were to contain only reference copies of correspondence, memoranda, minutes ofmeetings, reports, position papers, briefing materials, studies, and other nonrecord material maintained for convenience in office or individual files. Official copies of all permanently valuable State Department records were supposed to be included in the Central Files of the department. World War II and the subsequent Cold War, however, put a heavy strain on the record-keeping system at the department. Also, officials became more reluctant to send particularly sensitive or important records to the more general Central Files. As a result, many original documents, record copies, working papers, drafts, informal notes, and annotated copies of memoranda were incorporated into the Special Files. The Special File number comprises the last two digits ofthe year in which the file was retired or deactivated by the originating office or individual, a letter designation (D for department origination, F for origination at a Foreign Service post, and M for a special mission), and a final number that simply indicates the sequence in which a particular collection wasretired. For example. Special File 54-D-423 refers to 1954 as the year in which the file was deactivated, D as originating at the Department ofState, and it being the 423rd file retired that year. It should be noted, however, that not all files that have been retired are still in existence. Some have been consolidated with similar material or have been destroyed because of a lack of permanently valuable records.