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http://www.aircanada.com/en/travelin.../boarding.html
Priority Boarding is offered on all flights operated by Air Canada and Air Canada Express and allows eligible customers to board the aircraft first. On flights operated by aircraft with more than 50 seats, Priority Boarding also offers you a dedicated boarding lane which allows you the luxury of boarding at any time, even once general boarding has already begun. Learn the true meaning of 'board at your leisure'!