“ 298 (1) A defamatory libel is matter published, without lawful justification or excuse, that is likely to injure the reputation of any person by exposing him to hatred, contempt or ridicule, or that is designed to insult the person of or concerning whom it is published.

    Marginal note:Mode of expression

    (2) A defamatory libel may be expressed directly or by insinuation or irony

        (a) in words legibly marked on any substance; or

        (b) by any object signifying a defamatory libel otherwise than by words.”

It doesn't have to be an assertion, or even a written statement.