http://www.metmuseum.org/toah/works-of-art/36.25.1043 says "A kard is defined as a straight, single-edged dagger that is worn on the left side of the belt. Unlike most daggers, in which the narrow tang attached to the blade fits into a handle, the blades of these daggers are made with a flat steel tang of the same width as the blade."
"The matter of his kard was also resolved with charm. "The dagger is not a weapon," Sir Joscelin told his porter, who was struggling to wrest it from Mansur's belt and put it with the swords. "It is a decoration for such a gentleman as this, as we old crusaders know."" Mistress of the Art of Death by Ariana Franklin, p 191 of the Berkley paperback edition