The 1968-1976 PMO Priority Correspondence series, which dates from April 1968 to April 1976, is organized according to a subject filing system based on a decimal classification that was adopted by the offices of three Canadian prime ministers: Diefenbaker, Pearson, and Trudeau.
Within files, documents are in reverse chronological order.
The system utilized ten broad subject areas or classes:
000-99 General
100-199 Defence
200-299 Economy
300-399 Government
400-499 Law
500-599 Resources and Development
600-699 Social Welfare
700-799 Trade and Commerce
800-899 World Relations
900-999 History, Geography and Biography
Each class was, in turn, further divided into as many as ten divisions, which can be summarized as follows:
000 GENERAL
010 Philosophy
020 Education
040 Language and Ethnic Groups
050 Pure Science
060 Applied Science
070 Arts and Recreation
080 Literature
100 DEFENCE
110 Navy
120 Army
130 Air Force
140 Civil Defence 1
50 Defence Research
160 Defence Production
170 Defence Expenditure
180 War
200 ECONOMY
210 Labour
220 Land Economics
230 Currency and Banking
240 National Accounts 2
50 Public Finance
260 Production and Prices
270 Insurance
300 GOVERNMENT
310 Federal Government Executive
320 Senate
330 The House of Commons
340 The Judiciary
350 Federal Government Administration
360 Provincial Government 3
70 Municipal Government
380 Governments of other Countries
390 Political Parties
400 LAW
410 Constitutional Law
420 Criminal Law and Procedures
430 Crime and Delinquency
440 Penal Institutions and Police
450 Statutes of Canada
460 Statutes of the Provinces
470 Civil Law 4
80 Law of Other Countries 4
90 International Law
500 RESOURCES AND DEVELOPMENT
510 Agriculture
520 Fisheries
530 Forestry
540 Minerals and Fuel
550 Power
560 Furs and Wildlife Resources 5
70 Immigration and Citizenship
580 Population and Vital Statistics
600 SOCIAL WELFARE
610 Federal Health Activities 6
20 Provincial and Municipal Health
630 Federal-Provincial Welfare Services
640 Provincial Welfare Services
650 Veterans Health and Welfare
660 Health and Welfare Organizations
700 TRADE AND COMMERCE 7
10 Domestic Trade
720 Foreign Trade
730 Transportation and Communication
740 Manufactures
750 Construction
760 Purchasing and Stores
770 Publicity and Public Relations
780 Statistics
800 WORLD RELATIONS
810 Canada and the Commonwealth
820 Canada and the United Nations
830 Canada and the North Atlantic Treaty
840 Canada and Foreign Countries
850 Canada and the United States
860 Diplomatic Representation
870 Non-Governmental Organizations
880 Southeast Asia Treaty
890 Organization of American States
900 HISTORY, GEOGRAPHY AND BIOGRAPHY
910 Canadian History
920 Anglo-American History
930 History of Foreign Countries
940 Physical Geography 9
50 Economic Geography
960 Political Geography
970 Geography of Foreign Countries
980 Exploration and Travel
990 Biography, Genealogy and Heraldry
The finding aid for this part of the Priority Series provides a list of files in numeric order, starting with 001 and ending with 999.
In addition, the entire sub-series is indexed both by name and by subject in a comprehensive card index. The card index is available to researchers in volumes 759 to 996.
It should be noted that from September 1969 to April 1976, the PMO General Correspondence Series, MG 26 O 8, served as a kind of chronological registry for nonsecret PMO correspondence, so that copies of many Priority letters were interfiled, in chronological order, with the General Correspondence.