§1. The decree of citation to the trial must be communicated immediately to the respondent and at the same time to others who must appear.
§2. The libellus which introduces litigation is to be attached to the citation unless for grave causes the judge determines that the libellus must not be made known to the party before that party makes a deposition in the trial.
§3. If litigation is introduced against someone who does not have the free exercise of his or her rights or the free administration of the things in dispute, the citation must be communicated, as the case may be, to the guardian, curator, or special procurator, that is, the one who is bound to undertake the trial in the name of that person according to the norm of law.
Source: Code of Canon Law (Vatican.va)