Original: This same Synod then added these Canons to two other documents , both of which were in common use by the Dutch Church at the time : the Heidelberg Catechism ( 1563 ) and the Belgic Confession ( 1561 ) .
Simplified: This meeting then added the Canons of Dort to two other documents , the Belgic Confession and the Heidelberg Catechism , which were both commonly used by the Dutch Church at this time .