That none but a bishop consecrates chrism
Although the custom is almost everywhere preserved that only a bishop consecrates chrism, yet because in some places or provinces the presbyters are said to bless chrism, it was agreed that none but the bishop shall henceforth bless chrism: and he shall send it into his diocese in such fashion that deacons and subdeacons shall be sent from each church to the bishop before Easter, so that the chrism which the bishop has blessed shall arrive in time for Easter. While the bishops have the undoubted right to bless chrism at any time, presbyters may do nothing without the knowledge of the bishop: it is decreed that the deacon may not give chrism but the presbyter may do so in the absence of the bishop, or in his presence if he commands. The archdeacon should always remember to remind this constitution to the bishops whether they are present or not, so that bishops will guard it and presbyters will not neglect it.
(trans. Whitakker 2003: 155 in Johnson 2007: 181, slightly altered)