On the first day of the Conference, the Donatists challenged the list of the signatures of the Catholic bishops on the document in which they had assigned their representatives. A roll call followed, in which the tribune Marcellinus, who presided, called the Catholic bishops one by one, and their Donatist counterparts were to identify them. Then the roll call proceeded in the opposite way, with the Donatist bishops identified by the Catholics.

The expression of the Donatist Bishop Gaudentius about "not having an opponent" may be technically true even if a Catholic presbyter was present in Zerta: he would not be considered an "opponent" worthy of being mentioned as such by a bishop.