The amendment is quite simple. The finance minister would report to Canadians how much the carbon tax cost them, depending on the quartile of income in which they find themselves. The lowest-income quarter, the two middle-income quarters, and then the highest-income quarter of Canadian households would pay this tax, and they would find out how much in carbon tax they paid every single year. This tax is insidious, because its costs are hidden and are not itemized in the consumer goods Canadians buy. Unlike with other taxes, they can't see it on the receipt when they purchase something at a retail outlet.
On May 23rd, 2018. See this statement in context.