http://www.aircanada.com/en/travelin...lftagging.html

Customers may now save even more time with convenient and quick Self-Tagging offered by Air Canada in the following airports: Montreal, Toronto and Vancouver. This is a new service offered by Air Canada, and it will become more widely available as it is implemented.

Customers checking in at the counter as before, as well as those using web check-in, mobile check-in or kiosk check-in, are now able to take advantage of self-tagging by printing and attaching their own baggage tags, and carrying their baggage to the Baggage Drop-off.

If you have used WEB or MOBILE check-in before arriving to the airport:
At an available kiosk in the airport, enter your Booking Reference Number, or scan the bar code you printed following your Web Check-in;
When your flight booking comes up, press 'Reprint' and follow the on-screen directions to print your baggage tags, receipt and boarding pass;
Attach the tags and take the baggage to the Baggage Drop-off;
Proceed to your gate as normal.
To use the SELF-SERVICE Check-in KIOSKs:
At an available kiosk in the airport, enter your Booking Reference Number;
When your flight booking comes up, follow the on-screen directions in sequence, and print out your baggage tags;
Attach the tags and take the baggage to the Baggage Drop-off;
Proceed to your gate as normal.