Code of Canon Law 1495
1496 §1. A person, who through at least probable arguments has shown a right over something held by another and the threat of damage unless the thing is placed in safekeeping, has the right to obtain its sequestration from the judge.
§2. In similar circumstances, a person can obtain an order to restrain another from the exercise of a right.
1497 §1. Sequestration of a thing is also allowed as security for a loan provided that the right of the creditor is sufficiently evident.
§2. Sequestration can also be extended to the goods of the debtor which are discovered in the possession of others under any title and to the loans of the debtor.
1498 Sequestration of a thing and restraint upon the exercise of a right can in no way be decreed if the harm which is feared can be repaired in another way and suitable security for its repair is offered.
1499 A judge who grants the sequestration of a thing or a restraint upon the exercise of a right can first impose an obligation upon the person to compensate for damages if that person’s right is not proven.
1500 The prescripts of the civil law of the place where the object whose possession is in question is located are to be observed regarding the nature and force of a possessory action.
1501 A judge cannot adjudicate a case unless the party concerned or the promoter of justice has presented a petition according to the norm of the canons.
1502 A person who wishes to bring another to trial must present to a competent judge a libellus which sets forth the object of the controversy and requests the services of the judge.
1503 §1. The judge can accept an oral petition whenever the petitioner is impeded from presenting a libellus or the case is easily investigated and of lesser importance.
§2. In either case, however, the judge is to order the notary to put the act into writing; the written record must be read to and approved by the petitioner and has all the legal effects of a libellus written by the petitioner.
1504 The libellus, which introduces litigation, must:
1/ express the judge before whom the case is introduced, what is being sought and by whom it is being sought;
2/ indicate the right upon which the petitioner bases the case and, at least generally, the facts and proofs which will prove the allegations;
3/ be signed by the petitioner or the petitioner’s procurator, indicating the day, month, and year, and the address where the petitioner or procurator lives or where they say they reside for the purpose of receiving the acts;
4/ indicate the domicile or quasi-domicile of the respondent.
1505 §1. When a single judge or the president of a collegiate tribunal has seen that the matter is within his competence and the petitioner does not lack legitimate personal standing in the trial, he must accept or reject the libellus as soon as possible by decree.
§2. A libellus can be rejected only:
1/ if the judge or tribunal is incompetent;
2/ if without doubt it is evident that the petitioner lacks legitimate personal standing in the trial;
3/ if the prescripts of CIC 1504, nn. 1-3 have not been observed;
4/ if it is certainly clear from the libellus itself that the petition lacks any basis and that there is no possibility that any such basis will appear through a process.
§3. If the libellus has been rejected because of defects which can be corrected, the petitioner can resubmit a new, correctly prepared libellus to the same judge.
§4. A party is always free within ten available days to make recourse with substantiating reasons against the rejection of a libellus either to the appellate tribunal or to the college if the libellus was rejected by the presiding judge; the question of the rejection is to be decided as promptly as possible (expeditissime).
1506 If within a month from the presentation of the libellus the judge has not issued a decree which accepts or rejects the libellus according to the norm of CIC 1505, the interested party can insist that the judge fulfill his function. If the judge takes no action within ten days from the request, then the libellus is to be considered as accepted. 
1507 §1. In the decree which accepts the libellus of the petitioner, the judge or the presiding judge must call the other parties to trial, that is, cite them to the joinder of the issue, establishing whether they must respond in writing or present themselves before the judge to come to agreement about the doubts. If from the written responses the judge perceives it necessary to convene the parties, the judge can establish that by a new decree.
§2. If the libellus is considered as accepted according to the norm of CIC 1506, the decree of citation to the trial must be issued within twenty days from the request mentioned in that canon.
§3. If the litigating parties de facto present themselves before the judge to pursue the case, however, there is no need for a citation, but the notary is to note in the acts that the parties were present for the trial.
1508 §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.
1509 §1. The notification of citations, decrees, sentences, and other judicial acts must be made through the public postal services or by some other very secure method according to the norms established in particular law.
§2. The fact of notification and its method must be evident in the acts.
1510 A respondent who refuses to accept the document of citation or who prevents its delivery is considered to be legitimately cited.
1511 If the citation was not communicated legitimately, the acts of the process are null, without prejudice to the prescript of CIC 1507, §3.
1512 When the citation has been communicated legitimately or the parties have appeared before the judge to pursue the case:
1/ the matter ceases to be res integra;
2/ the case becomes proper to the otherwise competent judge or tribunal before which the action was initiated;
3/ the jurisdiction of a delegated judge is fixed in such a way that it does not cease when the authority of the one delegating expires;
4/ prescription is interrupted unless other provision is made;
5/ the litigation begins to be pending; therefore, the principle while litigation is pending, nothing is to be altered immediately takes effect.
1513 §1. The joinder of the issue (contestatio litis) occurs when the terms of the controversy, derived from the petitions and responses of the parties, are defined through a decree of the judge.
§2. The petitions and responses of the parties, besides those in the libellus which introduces the litigation, can be expressed either in a response to the citation or in the oral declarations made before the judge; in more difficult cases, however, the judge must convene the parties to resolve the doubt or doubts which must be answered in the sentence.
§3. The decree of the judge must be communicated to the parties; unless they have already agreed to the terms, the parties can make recourse to the judge within ten days in order to change them; a decree of the judge, however, must resolve the question as promptly as possible (expeditissime).
1514 Once established, the terms of the controversy cannot be changed validly except by a new decree, for a grave cause, at the request of a party, and after the other parties have been heard and their arguments considered.
1515 After the issue has been joined, the possessor of the property of another ceases to be in good faith; therefore, if the possessor is sentenced to restore the property, the person must also return the profits made from the day of the joinder and repair any damages.
1516 After the issue has been joined, the judge is to prescribe a suitable time for the parties to present and complete the proofs.
1517 A trial begins with the citation; it ends not only by the pronouncement of a definitive sentence but also by other methods defined by law.
1518 If the litigating party dies, changes status, or ceases from the office in virtue of which action is taken:
1/ if the case has not yet been concluded, the trial is suspended until the heir of the deceased, the successor, or an interested party resumes the litigation;
2/ if the case has been concluded, the judge must proceed to the additional acts, after having cited the procurator, if there is one, or otherwise the heir of the deceased or the successor.
1519 §1. If the guardian, curator, or procurator who is necessary according to the norm of CIC 1481, §§1 and 3 ceases from that function, the trial is suspended in the meantime.
§2. The judge, however, is to appoint another guardian or curator as soon as possible; the judge can appoint a procurator for the litigation if the party has neglected to do so within the brief time period established by the judge.
1520 If the parties, without any impediment, propose no procedural act for six months, the trial is abated.
Particular law can establish other terms of abatement.
1521 Abatement takes effect by the law itself against all persons, including minors or those equivalent to minors, and must be declared ex officio, without prejudice to the right of seeking indemnity against guardians, curators, administrators, or procurators, who have not proved that they were not negligent.
1522 Abatement extinguishes the acts of the process but not the acts of the case; indeed these acts can also have force in another trial provided that the case involves the same persons and the same issue; regarding those not party to the case, however, the acts have no force other than that of documents.
1523 Each litigant is to bear the expenses of the abated trial which that litigant has incurred.
1524 §1. The petitioner can renounce the trial at any stage or grade of the trial; likewise both the petitioner and the respondent can renounce either all or only some of the acts of the process.
§2. To renounce a trial, guardians and administrators of juridic persons need the counsel or consent of those whose involvement is required to place acts which exceed the limits of ordinary administration.
§3. To be valid, a renunciation must be written and signed by the party or by a procurator of the party who has a special mandate to do so; it must be communicated to the other party, accepted or at least not challenged by that party, and accepted by the judge.
1525 A renunciation accepted by the judge has the same effects for the acts renounced as the abatement of the trial; it also obliges the renouncing party to pay the expenses for the acts renounced.
1526 §1. The burden of proof rests upon the person who makes the allegation.
§2. The following do not need proof:
1/ matters presumed by the law itself;
2/ facts alleged by one of the contending parties and admitted by the other unless the law or the judge nevertheless requires proof.
1527 §1. Proofs of any kind which seem useful for adjudicating the case and are licit can be brought forward.
§2. If a party insists that a proof rejected by a judge be accepted, the judge is to decide the matter as promptly as possible (expeditissime).
1528 If a party or a witness refuses to appear before the judge to testify, it is permissible to hear them through a lay person designated by the judge or to require of them a declaration either before a notary public or in any other legitimate manner.
1529 Except for a grave cause, the judge is not to proceed to collect the proofs before the joinder of the issue.
1530 The judge can always question the parties to draw out the truth more effectively and indeed must do so at the request of a party or to prove a fact which the public interest requires to be placed beyond doubt.
1531 §1. A party legitimately questioned must respond and must tell the whole truth.
§2. If a party refuses to respond, it is for the judge to decide what can be inferred from that refusal concerning the proof of the facts.
1532 In cases where the public good is at stake, the judge is to administer an oath to the parties to tell the truth or at least to confirm the truth of what they have said unless a grave cause suggests otherwise; the same can be done in other cases according to the judge’s own prudence.
1533 The parties, the promoter of justice, and the defender of the bond can present the judge with items about which the party is to be questioned.
1534 The provisions of cann. CIC 1548, §2, n. 1, CIC 1552, and CIC 1558-1565 concerning witnesses are to be observed to the extent possible when questioning the parties.
1535 A judicial confession is the written or oral assertion of some fact against oneself before a competent judge by any party concerning the matter of the trial, whether made spontaneously or while being questioned by the judge.
1536 §1. The judicial confession of one party relieves the other parties from the burden of proof if it concerns some private matter and the public good is not at stake.
§2. In cases which regard the public good, however, a judicial confession and declarations of the parties which are not confessions can have a probative force which the judge must evaluate together with the other circumstances of the case; the force of full proof cannot be attributed to them, however, unless other elements are present which thoroughly corroborate them.
1537 After considering all the circumstances, it is for the judge to decide how much value must be accorded an extrajudicial confession introduced into the trial.
1538 A confession or any other declaration of a party lacks any force if it is shown that it was made due to an error of fact or extorted by force or grave fear.
1539 In any kind of trial, proof by means of both public and private documents is allowed.
1540 §1. Public ecclesiastical documents are those which a public person has drawn up in the exercise of that person’s function in the Church, after the solemnities prescribed by law have been observed.
§2. Public civil documents are those which the laws of each place consider to be such.
§3. Other documents are private.
1541 Unless contrary and evident arguments prove otherwise, public documents are to be trusted concerning everything which they directly and principally affirm.
1542 A private document, whether acknowledged by a party or approved by the judge, has the same force of proof against the author or signatory and those deriving a case from them as an extrajudicial confession. It has the same force against those who are not parties to the case as declarations of the parties which are not confessions, according to the norm of CIC 1536, §2.
1543 If the documents are shown to have been erased, emended, falsified, or otherwise defective, it is for the judge to decide what value, if any, must be afforded them.
1544 Documents do not have probative force in a trial unless they are originals or authentic copies and deposited at the tribunal chancery so that the judge and the opposing party can examine them.
1545 The judge can order a document common to both parties to be presented in the process.
1546 §1. Even if documents are common, no one is bound to present those which cannot be communicated without danger of harm according to the norm of CIC 1548, §2, n. 2 or without danger of violating an obligation to observe secrecy.
§2. Nonetheless, if at least some small part of a document can be transcribed and presented in copy without the above-mentioned disadvantages, the judge can decree that it be produced.
1547 Proof by means of witnesses is allowed under the direction of the judge in cases of any kind.
1548 §1. When the judge questions witnesses legitimately, they must tell the truth.
§2. Without prejudice to the prescript of CIC 1550, §2, n. 2, the following are exempted from the obligation to respond:
1/ clerics regarding what has been made known to them by reason of sacred ministry; civil officials, physicians, midwives, advocates, notaries, and others bound by professional secrecy even by reason of having given advice, regarding those matters subject to this secrecy;
2/ those who fear that from their own testimony ill repute, dangerous hardships, or other grave evils will befall them, their spouses, or persons related to them by consanguinity or affinity.
1549 All persons can be witnesses unless the law expressly excludes them in whole or in part.
1550 §1. Minors below the fourteenth year of age and those of limited mental capacity are not allowed to give testimony; they can, however, be heard by a decree of the judge which declares such a hearing expedient.
§2. The following are considered incapable:
1/ the parties in the case or those who stand for the parties at the trial, the judge and the judge’s assistants, the advocate, and others who assist or have assisted the parties in the same case;
2/ priests regarding all matters which they have come to know from sacramental confession even if the penitent seeks their disclosure; moreover, matters heard by anyone and in any way on the occasion of confession cannot be accepted even as an indication of the truth.
1551 The party who has introduced a witness can renounce the examination of that witness; the opposing party, however, can request that the witness be examined nevertheless.
1552 §1. When proof through witnesses is requested, their names and domicile are to be communicated to the tribunal.
§2. The items of discussion about which questioning of the witnesses is sought are to be presented within the time period set by the judge; otherwise, the request is to be considered as abandoned.
1553 It is for the judge to curb an excessive number of witnesses.
1554 Before the witnesses are examined, their names are to be communicated to the parties; if in the prudent judgment of the judge, however, that cannot be done without grave difficulty, it is to be done at least before the publication of the testimonies.
1555 Without prejudice to the prescript of CIC 1550, a party can request the exclusion of a witness if a just cause for the exclusion is shown before the questioning of the witness.
1556 The citation of a witness occurs through a decree of the judge legitimately communicated to the witness.
1557 A witness who has been cited properly is to appear or to inform the judge of the reason for the absence.
1558 §1. Witnesses must be examined at the tribunal unless the judge deems otherwise.
§2. Cardinals, patriarchs, bishops, and those who possess a similar favor by civil law are to be heard in the place they select.
§3. The judge is to decide where to hear those for whom it is impossible or difficult to come to the tribunal because of distance, sickness, or some impediment, without prejudice to the prescripts of cann. CIC 1418 and CIC 1469, §2.
1559 The parties cannot be present at the examination of the witnesses unless the judge has decided to admit them, especially when the matter concerns a private good. Their advocates or procurators, however, can be present unless the judge has decided that the examination must proceed in secret due to the circumstances of the matters and persons.
1560 §1. Each witness must be examined separately.
§2. If witnesses disagree among themselves or with a party in a grave matter, the judge, after having removed discord and scandal insofar as possible, can have those who disagree meet together or confront one another.
1561 The judge, the judge’s delegate, or an auditor examines the witness; the examiner must have the assistance of a notary. Consequently, if the parties, the promoter of justice, the defender of the bond, or the advocates present at the examination have any questions to be put to the witness, they are to propose them not to the witness but to the judge or the one who takes the place of the judge, who is to ask the questions, unless particular law provides otherwise.
1562 §1. The judge is to call to the attention of the witness the grave obligation to speak the whole truth and only the truth.
§2. The judge is to administer an oath to the witness according to CIC 1532; a witness who refuses to take it, however, is to be heard without the oath.
1563 The judge is first of all to establish the identity of the witness, then ask what relationship the witness has with the parties, and, when addressing specific questions to the witness concerning the case, also inquire about the sources of his or her knowledge and the precise time when the witness learned what he or she asserts.
1564 The questions are to be brief, accommodated to the mental capacity of the person being questioned, not comprised of several points at the same time, not deceitful or deceptive or suggestive of a response, free from any kind of offense, and pertinent to the case being tried.
1565 §1. Questions must not be communicated to the witnesses beforehand.
§2. Nonetheless, if the matters about which testimony must be given are so remote to memory that they cannot be affirmed with certainty unless previously recalled, the judge can advise the witness beforehand on some matters if the judge thinks this can be done without danger.
1566 Witnesses are to give testimony orally and are not to read written materials unless they are computations and accounts; in this case, they can consult the notes which they brought with them.
1567 §1. The notary is to write down the response immediately and must report the exact words of the testimony given, at least in what pertains to those points which touch directly upon the material of the trial.
§2. The use of a tape recorder can be allowed, provided that the responses are afterwards transcribed and, if possible, signed by the deponents.
1568 The notary is to make mention in the acts of whether the oath was taken, excused, or refused, of the presence of the parties and other persons, of the questions added ex officio, and in general of everything worth remembering which may have occurred while the witnesses were being examined.
1569 §1. At the end of the examination, what the notary has written down from the deposition must be read to the witness, or what has been recorded with the tape recorder during the deposition must be played, giving the witness the opportunity to add, suppress, correct, or change it.
§2. Finally, the witness, the judge, and the notary must sign the acts.
1570 Although already examined, witnesses can be recalled for examination before the acts or testimonies are published, either at the request of a party or ex officio, if the judge decides it is necessary or useful, provided that there is no danger of collusion or corruption.
1571 Both the expenses which the witnesses incurred and the income which they lost by giving testimony must be reimbursed to them according to the just assessment of the judge.
1572 In evaluating testimony, the judge, after having requested testimonial letters if necessary, is to consider the following:
1/ what the condition or reputation of the person is;
2/ whether the testimony derives from personal knowledge, especially from what has been seen or heard personally, or whether from opinion, rumor, or hearsay;
3/ whether the witness is reliable and firmly consistent or inconsistent, uncertain, or vacillating;
4/ whether the witness has co-witnesses to the testimony or is supported or not by other elements of proof.
1573 The testimony of one witness cannot produce full proof unless it concerns a qualified witness making a deposition concerning matters done ex officio, or unless the circumstances of things and persons suggest otherwise.
1574 The assistance of experts must be used whenever the prescript of a law or of the judge requires their examination and opinion based on the precepts of art or science in order to establish some fact or to discern the true nature of some matter.
1575 After having heard the parties and their suggestions, it is for the judge to appoint the experts or, if the case warrants, to accept reports already drawn up by other experts.
1576 Experts are excluded or can be objected to for the same reasons as a witness.
1577 §1. Attentive to what the litigants may bring forward, the judge is to determine in a decree the individual items upon which the services of the expert must focus.
§2. The acts of the case and other documents and aids which the expert can need to fulfill his or her function correctly and faithfully must be turned over to the expert.
§3. After having heard the expert, the judge is to determine the time within which the expert must complete the examination and produce the report.
1578 §1. Each of the experts is to prepare a report separate from the others unless the judge decrees that one report signed by the experts individually be drawn up; if this is done, differences of opinion, if there are any, are to be noted carefully.
§2. Experts must indicate clearly by what documents or other suitable means they gained certainty of the identity of the persons, things, or places, by what manner and method they proceeded in fulfilling the function entrusted to them, and above all on which arguments they based their conclusions.
§3. The judge can summon the expert to supply explanations which later seem necessary.
1579 §1. The judge is to weigh carefully not only the conclusions of the experts, even if they are in agreement, but also the other circumstances of the case.
§2. When giving reasons for the decision, the judge must express what considerations prompted him or her to accept or reject the conclusions of the experts.
1580 The judge must justly and equitably determine the expenses and fees to be paid to the experts, with due regard for particular law.
1581 §1. The parties can designate private experts whom the judge must approve.
§2. If the judge allows them, the private experts can inspect the acts of the case insofar as necessary and attend the presentation of the expert testimony; moreover, they can always present their own report.
1582 If, in order to decide a case, the judge considers it opportune to visit some place or to inspect some thing, the judge, after having heard the parties, is to order it by a decree describing in summary fashion those things which must be exhibited during the visit or inspection.
1583 When the visit or inspection has been completed, a report about it is to be drafted.
1584 A presumption is a probable conjecture about an uncertain matter; a presumption of law is one which the law itself establishes; a human presumption is one which a judge formulates.
1585 A person who has a favorable presumption of law is freed from the burden of proof, which then falls to the other party.
1586 The judge is not to formulate presumptions which are not established by law unless they are directly based on a certain and determined fact connected with the matter in dispute.
1587 An incidental case arises whenever, after the trial has begun through the citation, a question is proposed which nevertheless pertains to the case in such a way that it frequently must be resolved before the principal question, even if it was not expressly contained in the libellus which introduced the litigation.
1588 An incidental case is proposed in writing or orally before the judge competent to decide the principal case, indicating the connection between this and the principal case.
1589 §1. After having received the petition and heard the parties, the judge is to decide as promptly as possible (expeditissime)whether the proposed incidental question seems to have a foundation and a connection with the principal trial or rather must be rejected at the outset. If the judge admits the incidental question, the judge is to decide whether it is of such gravity that it must be resolved by an interlocutory sentence or by a decree.
§2. If the judge decides not to resolve the incidental question before the definitive sentence, however, the judge is to decree that the question will be considered when the principal case is decided.
1590 §1. If the incidental question must be resolved by sentence, the norms for the oral contentious process are to be observed unless the judge decides otherwise due to the gravity of the matter.
§2. If the matter must be resolved by decree, however, the tribunal can entrust the matter to an auditor or the presiding judge.
1591 Before the principal case is completed, the judge or the tribunal can revoke or reform the decree or interlocutory sentence for a just reason either at the request of a party or ex officio after the parties have been heard.
1592 §1. If the cited respondent has neither appeared nor given a suitable excuse for being absent or has not responded according to the norm of CIC 1507, §1, the judge, having observed what is required, is to declare the respondent absent from the trial and decree that the case is to proceed to the definitive sentence and its execution.
§2. Before issuing the decree mentioned in §1, the judge must be certain that a legitimately executed citation has reached the respondent within the useful time, even by issuing a new citation if necessary.
1593 §1. If the respondent appears at the trial later or responds before a decision in the case, the respondent can offer conclusions and proofs, without prejudice to the prescript of CIC 1600; the judge, however, is to take care that the trial is not prolonged intentionally through longer and unnecessary delays.
§2. Even if the respondent did not appear or respond before a decision in the case, the respondent can use challenges against the sentence; if the respondent proves that there was a legitimate impediment for being detained and there was no personal fault in its not being made known beforehand, the respondent can use a complaint of nullity.
1594 If the petitioner has not appeared on the day and at the hour prescribed for the joinder of the issue and has not offered a suitable excuse:
1/ the judge is to cite the petitioner again;
2/ if the petitioner does not comply with the new citation, the petitioner is presumed to have renounced the trial according to the norm of cann. CIC 1524-1525;
3/ if the petitioner later wishes to intervene in the process, CIC 1593 is to be observed.
1595 §1. A petitioner or respondent who is absent from the trial and has not given proof of a just impediment is obliged both to pay the expenses of the litigation which have accrued because of the absence and to indemnify the other party if necessary.
§2. If both the petitioner and the respondent were absent from the trial, they are obliged in solidum to pay the expenses of the litigation.
Code of Canon Law 1495