This series makes up the first of annual single number correspondence files kept by the Federal Capital Office, Melbourne. According to the control records for the series - CRS A 213 - this system was used for  a year and a half with 6,512 registrations but only six files of the series are extant. The official stamp of the office, which registered the series, was square-shaped and identified with the title of the office - "Federal Capital Office, Melbourne". Most of the folios were marked with this stamp together with the receiving date and reference number, serving to identify these papers as those of first system of records. There was a great deal of top-numbering due to the early practice of registering the single items of correspondence rather than registering files. The identifying file number was usually the last registered number. This system was followed by Australian Archives when arranging the loose folios (without file covers) into manila folders according to their subject matter, dating and stamp numbers. It appears that only one file item no. 17/280 "Boiler inspections - Canberra" retained the original file cover of white linen reinforced material labelled with blue printing as;- "Commonwealth of Australia, Department of Home Affairs, File Papers, Subject". There was also a complicated secondary alphabetical control arrangement using variations of the letters B-E and apparently referring to a type of functional
classification divided under four headings - Administration,
Accommodation, Special (resources) and Services. Although the number register for this series - CRS A213 - is notated with these letters there is only one of the extant filesso marked - item no. 16/2277 with ECCBF for "Ecclesiastic".
 According to the titles entered in the Number Register, the records deal mainly with construction matters of the Federal Capital Territory. At the commencement of 1916 much of the correspondence was concerned with employment and staff problems as well as expenditure of travel between Sydney, Melbourne and Canberra. For the remaining period till June 1917 the papers related to all subjects pertaining to the planning of the Capital City, including decisions about dams, water-works bridges, electricity, arsenal sites, Duntroon Military College, building materials, machinery, telegraph installations, railways, schools and the perennial staffing concerns. The six extant files cover the same wide range of subjects.