Title II

Only that custom introduced by the community of the faithful and approved by the legislator has the force of law, according to the following canons.

§ 1.

No custom which is contrary to divine law can obtain the force of law.

§ 2.

Unless (nisi) it be a reasonable one, no custom which is contrary to or apart from (praeter ius) canon law can obtain the force of law; however, a custom which is expressly reprobated in law is not a reasonable one.

No custom obtains the force of law unless (nisi) it has been observed with the intention of introducing a law by a community capable at least of receiving law.

Unless (nisi) it has been specifically approved by the competent legislator, a custom contrary to the current canon law or one which is apart from (praeter ius) canon law obtains the force of law only when it has been legitimately observed for thirty continuous and complete years; only a centenary or immemorial custom can prevail over a canon which contains a clause forbidding future customs.

Custom is the best interpreter of laws.

With due regard for the prescription of can. 5, a custom, whether it is contrary to or apart from the law (praeter legem), is revoked by a contrary custom or law, however, unless (nisi) it makes express mention of centenary or immemorial customs, a law does not revoke them, nor does a universal law revoke particular customs.