510. A custom expressly disapproved of in law is not reasonable or legitimate, and cannot derogate from an existing law, nor establish a new law (Canons 27, 28). 511. The time prescribed by the Code of Canon Law for the acquisition of legal force by customs that have not the personal consent of the lawgiver is as follows: (a) forty continuous and complete years are required to unmake an ordinary law; one hundred years to unmake a law that forbids future contrary custom (Canon 27, Sec. 1); (b) forty continuous and complete years are likewise required to make a new law (Canon 28). 512. The effect of the Code on customs previously existing was considered above under 421. 513. Like the written law, custom ceases: (a) from within, when its purpose has ceased entirely; (b) from without, when it is abrogated by desuetude, or by a contrary law or custom (Canon 30). 514. Laws in a Wide Sense.--In addition to laws strictly so-called, there are laws in a wide sense, commands or provisions made by ecclesiastical superiors that have not all the conditions given above (see 285) for law. Such are: (a) precepts, which differ from law, because they are given not to the community or permanently, but to individuals or temporarily; (b) rescripts, which are given with regard to particular cases and without the solemnity of law; (c) privileges, which are not obligatory; (d) dispensations, which are relaxations of law granted to individuals. 515. A precept is a command given to individuals, or for an individual case, by a competent superior. (a) It is a command obliging in conscience, and so differs from counsel, desire, exhortation. (b) It is given to individuals, and thus differs from law, which has the character of universality and stability. A precept may be imposed on a community, but even then it is particular, as being given only for an individual case or for a certain length of time--for a month or a year, or during the lifetime of the superior. (c) It is given by a competent superior. Even here precept differs from law, since laws can be made only by one who has jurisdictional or public authority (see above, 285), while precepts may be given also by those who have only dominative or private authority (as parents, heads of families, husbands, employers, abbesses). In canonical matters precepts may be given by religious superiors, parish priests, rectors of seminaries, and for the court of conscience by the confessor. 516. Precept is similar to law: (a) as to its object, which must be just, good, and possible of observance; (b) as to its binding force, since it can be imposed even on those who are unwilling.