§1. Each diocese is to have a special institute which is to collect goods or offerings for the purpose of providing, according to the norm of can. 281, for the support of clerics who offer service for the benefit of the diocese, unless provision is made for them in another way.
§2. Where social provision for the benefit of clergy has not yet been suitably arranged, the conference of bishops is to take care that there is an institute which provides sufficiently for the social security of clerics.
§3. Insofar as necessary, each diocese is to establish a common fund through which bishops are able to satisfy obligations towards other persons who serve the Church and meet the various needs of the diocese and through which the richer dioceses can also assist the poorer ones.
§4. According to different local circumstances, the purposes mentioned in §§2 and 3 can be obtained more suitably through a federation of diocesan institutes, through a cooperative endeavor, or even through an appropriate association established for various dioceses or for the entire territory of the conference of bishops.
§5. If possible, these institutes are to be established in such a way that they also have recognition in civil law.
Source: Code of Canon Law (Vatican.va)