Sure. Thanks for the question.
In a previous motion, which I believe was carried, that term is defined expressly. If Bill C-21 becomes law, it will come to mean a barrel for any firearm or a slide for a handgun.
There is also an opportunity for the government to prescribe parts to add to that list. Let's say, for example, a part is identified as specifically amenable to the creation of a ghost gun. That part can be particularly isolated by regulation.