You will notice that some citations for acts contain the abbreviation “Supp.” (short for “supplement”). An example of this would be “Competition Tribunal Act, R.S.C. 1985, c. 19 (2nd Supp.)”. But what does this mean?
The main volumes of R.S.C. 1985 contain acts that came into being before or on December 31, 1984, but R.S.C. 1985 was not brought into force until December 12, 1988. So what happened to all the legislation made between January 1, 1985 and December 11, 1988? If you guessed that they became the supplements to R.S.C. 1985 you would be correct; for example R.S.C. 1985 (1st Supp.) contains the acts that received Royal Assent in 1985 and R.S.C. 1985 (2nd Supp.) contains the acts that received Royal Assent in 1986.
The supplements to R.S.C. 1985 have different in force dates depending on which supplement they are in; the BC Courthouse Libraries has produced a helpful guide to the various in force dates.
You will also find supplements in provincial legislation, e.g. R.S.B.C. 1996 included any acts that had received Royal Assent but had not come into force as of December 31, 1996 (the cut off date for the Revised Statutes) as supplements.