Okay.
We approved of it at the time.
There is then a process whereby states have to choose to sign the treaty, and then once they've signed the treaty, deposit their instruments of ratification, which is a fancy way of saying that we are demonstrating that we meet all of the obligations that we signed on to. Once a certain threshold of states signs and deposits their ratification, the treaty is considered to be in force. Others, like Canada, which chose not to sign the treaty at the time, then have to accede to the treaty.
Bill C-47 reflects the government's decision to accede to the treaty afterwards.