CODE OF CANON LAW
BOOK I. GENERAL NORMS
GENERAL DECREES AND INSTRUCTIONS (Cann. 29 - 34)
Can. 29 General decrees, by which a competent legislator issues common prescripts for a community capable of receiving law, are laws properly speaking and are governed by the prescripts of the canons on laws.
Can. 30 A person who possesses only executive power is not able to issue the general decree mentioned in can. 29 unless, in particular cases, it has been expressly granted to that person by a competent legislator according to the norm of law and the conditions stated in the act of the grant have been observed.
Can. 31 §1. Those who possess executive power are able to issue, within the limits of their competence, general executory decrees, namely, those which more precisely determine the methods to be observed in applying the law or which urge the observance of laws.
§2. With respect to the promulgation and suspensive period (vacatio) of the decrees mentioned in §1, the prescripts of can. 8 are to be observed.
Can. 32 General executory decrees oblige those who are bound by the laws whose methods of application the same decrees determine or whose observance they urge.
Can. 33 §1. General executory decrees, even if they are issued in directories or in documents of another name, do not derogate from laws, and their prescripts which are contrary to laws lack all force.
§2. Such decrees cease to have force by explicit or implicit revocation made by competent authority as well as by cessation of the law for whose execution they were given. They do not, however, cease when the authority of the one who established them expires unless the contrary is expressly provided.
Can. 34 §1. Instructions clarify the prescripts of laws and elaborate on and determine the methods to be observed in fulfilling them. They are given for the use of those whose duty it is to see that laws are executed and oblige them in the execution of the laws. Those who possess executive power legitimately issue such instructions within the limits of their competence.
§2. The ordinances of instructions do not derogate from laws. If these ordinances cannot be reconciled with the prescripts of laws, they lack all force.
§3. Instructions cease to have force not only by explicit or implicit revocation of the competent authority who issued them or of the superior of that authority but also by the cessation of the law for whose clarification or execution they were given.