Yes, there are a few different things. One major thing is the proportion of students who live in on-campus residences. Proving one's address can be a bit trickier for students living on campus, we've found when we've spoken to those students, given the frequency with which they will move on and off campus. Oftentimes, they have to seek out a formal letter of residence confirmation in order to take that to the polls. A lot of students aren't aware that's available, and some residence offices aren't aware that they should issue them. There's kind of an extra layer of bureaucracy created there, so I think on-campus students would definitely be one example.
I also think we have a growing population of international students in Canada, which is great, but having people trying to determine at what point they're eligible to vote in a Canadian election, what residence status they require, and things like that pertaining to their student visa sometimes adds layers of confusion as well.