§1. A conference of bishops can only issue general decrees in cases where universal law has prescribed it or a special mandate of the Apostolic See has established it either motu proprio or at the request of the conference itself.
§2. The decrees mentioned in §1, in order to be enacted validly in a plenary meeting, must be passed by at least a two thirds vote of the prelates who belong to the conference and possess a deliberative vote. They do not obtain binding force unless they have been legitimately promulgated after having been reviewed by the Apostolic See.
§3. The conference of bishops itself determines the manner of promulgation and the time when the decrees take effect.
§4. In cases in which neither universal law nor a special mandate of the Apostolic See has granted the power mentioned in §1 to a conference of bishops, the competence of each diocesan bishop remains intact, nor is a conference or its president able to act in the name of all the bishops unless each and every bishop has given consent.
Source: Code of Canon Law (Vatican.va)