The summary of Canon 3 is combined into one with Canon 5 which chastises only the bishops (and not bishops and presbyters) for the reproachable practices with the relics. Therefore, the term sacerdos has a double meaning in this phrase. In reference to the tenor of Canon 3 it means all the clerics that are allowed to celebrate mass (that is bishops and presbyters), and in reference to Canon 5 it means only the bishops.
The phrase "the stole hanging down over neck on both shoulders made a sign of the cross on the chest of the priest" means that the stole shall be crossed on the chest. The canon does distinguish here between the bishops and the presbyters, unlike later medieval tradition (wearing the stole uncrossed was the privilege of the bishops). For the custom of receiving the stole upon ordination see [440].