A federacy is essentially an extreme case of an asymmetric federation, either due to large differences in the level of autonomy, or the rigidity of the constitutional arrangements.
The second type reflects agreements which come out of national policy, opting out, and (depending on one's definition of the term) bilateral and ad hoc deals with specific provinces, none of which are entrenched in the constitution.
In practice, a degree of asymmetry is created as a result of the evolution of the Canadian federal experiment, individual federal-provincial agreements, and judicial interpretation.
[1] A recent example of asymmetry in the Canadian federation can be found in the terms of the September 2004 federal-provincial-territorial agreement on health care and the financing thereof.
It, however, provides a useful lever for those who want to decentralize the structure as a whole, transferring more powers from the centre to the provinces overall, a trend that dominated Canadian politics for decades.
From 1945 to 1968, Czechoslovakia operated under an asymmetric federal model, and the Slovak National Council appointed a Chairman of the Board of Trustees, de facto the Prime Minister of Slovakia.
Article 371-371J make special provisions for the states of Andhra Pradesh, Arunachal Pradesh, Assam, Gujarat, Goa, Karnataka, Mizoram, Manipur, Maharashtra, Nagaland, Sikkim, and Telangana.In Indonesia, although the form of state is unitary, four regions were given the special status of autonomy (keistimewaan) as provinces: Aceh, Jakarta, Yogyakarta and 5 provinces in West Papua.
International human rights activists have called Papua a 'fake autonomous province' due to the lack of real autonomy in the field.
In Italy, five regions (namely Sardinia, Sicily, Trentino-Alto Adige/Südtirol, Aosta Valley and Friuli-Venezia Giulia) have been granted special status of autonomy.
At the same time, Russian SFSR did not have its own Communist Party branch, whose First Secretaries de-facto served as a head of states of other Soviet Republics.
In Spain, which is either called an "imperfect federation"[7] or a "federation in all but its name",[8] the central government has granted different levels of autonomy to its substates, considerably more to the autonomous communities of Catalonia, the Basque Country, Valencia, Andalusia, Navarre and Galicia and considerably less to the others, out of respect for nationalist sentiment and rights these regions have enjoyed historically.
In the United Kingdom, England has no self-government and is ruled directly by the British Parliament, but Northern Ireland, Scotland, and Wales have varying degrees of autonomy.