This series consists of correspondence files used by the post to provide and store information necessary to the conduct of business with the host country (United States of America).

The series covers the whole range of records kept at the post, including:

.  all aspects of post administration;
.  consular functions incorporating immigration activities;
.  economic and trade relations;
.  aid and training matters;
.  internal and external affairs of the host country and other 
   countries within the post's representation, reporting and visiting
   responsibilities; and
.  background information on Australia.

The post adopted a filing system, introduced by External Affairs in 1948, which was used to some extent (with variations) by most of the overseas posts at that time. It was a multiple number system using primary numbers 1 to 200.

With the introduction of first uniform filing system in 1956, which had primary numbers of 1/- to 490/-, most posts top numbered files from the old system into the first uniform filing system. Because this system used the same primary numbers as the 1948 system, it is easy to confuse the two. Unfortunately, file date ranges are not always helpful as Central Office normally instructed staff to top number all items into the new system.

The outcome provided a loose structure of primary numbers 1 to 699, under the following groups:

  1 - 12  Administration of the Mission                         
 51 - 76  United Nations Administration                          
101 - 109 United Nations General Assembly                        
151 - 159 Policy and Security                                    
200 - 299 Economic and social matters                            
300 - 349 Specialised agencies                                    
350 - 415 Matters relating to colonial countries
451 - 463 Legal
500 - 549 Regional organisations and conferences
550 - 559 Australia
600 - 699 Other countries

For many years, departments with staff attached to diplomatic missions overseas (especially Immigration, Trade, Defence) were normally allocated filing numbers within the External/Foreign Affairs system. In particular, 62/- to 68/- for Immigration, 120/- for Trade and 205/- for Defence. This practice generally ceased for Immigration in 1989 with the introduction of the Universal migration case file system (CRS A8425).

Like many small missions, the Brasilia post did not change its file record system from the first to the second uniform filing system in 1975, probably due to small numbers, other priorities and small record holdings they continued to create records using the original system they commenced with in 1948.

New records are still being created and will continue to be as long as diplomatic relations are maintained with the host country.