Canon 1118

1. Defects which can render a sentence invalid can be introduced as an exception during any stage or grade of a trial; a

judge can likewise declare them ex officio. 2. Dilatory exceptions, especially those which concern the persons and the

manner of the trial, are to be proposed before the joinder of

issues (litis contestatio), unless they first emerged only after

it; and they are to be settled as soon as possible.