What is a petition for certiorari?

Section 1, Rule 65 of the Rules of Court provides:
SECTION 1. Petition for certiorari. When any tribunal, board or officer exercising judicial or quasi-judicial functions has acted without or in excess of its or his jurisdiction, or with grave abuse of discretion amounting to lack or excess of jurisdiction, and there is no appeal, nor any plain, speedy, and adequate remedy in the ordinary course of law, a person aggrieved thereby may file a verified petition in the proper court, alleging the facts with certainty and praying that judgment be rendered annulling or modifying the proceedings of such tribunal, board or officer, and granting such incidental reliefs as law and justice may require.

The petition shall be accompanied by a certified true copy of the judgment, order or resolution subject thereof, copies of all pleadings and documents relevant and pertinent thereto, and a sworn certification of non-forum shopping as provided in the third paragraph of Section 3, Rule 46.
Aside from the remedy of appeal discussed above, our jurisprudence is replete with cases holding that the plain and adequate remedy referred to in the foregoing rule is a motion for reconsideration of the assailed order or resolution, the filing of which is an indispensable condition to the filing of a special civil action for certiorari.[1] 

It is true that there are exceptions to the above rule, to wit: 

(a) where the order is a patent nullity, as where the court a quo has no jurisdiction; 
(b) where the questions raised in the certiorari proceedings have been duly raised and passed upon by the lower court, or are the same as those raised and passed upon in the lower court; 
(c) where there is an urgent necessity for the resolution of the question and any further delay would prejudice the interests of the Government or of the petitioner or the subject matter of the action is perishable; 
(d) where, under the circumstances, a motion for reconsideration would be useless; 
(e) where petitioner was deprived of due process and there is extreme urgency for relief; 
(f) where, in a criminal case, relief from an order of arrest is urgent and the granting of such relief by the trial court is improbable; 
(g) where the proceedings in the lower court are a nullity for lack of due process; 
(h) where the proceedings was ex parte or in which the petitioner had no opportunity to object; and 
(i) where the issue raised is one purely of law or public interest is involved.[2]
It must be emphasized that a writ of certiorari is a prerogative writ, never demandable as a matter of right, never issued except in the exercise of judicial discretion.[3] Hence, he who seeks a writ of certiorari must apply for it only in the manner and strictly in accordance with the provisions of the law and the Rules.[4] 

[1] Santos v. Cruz, 519 Phil. 61, 68, (2006), citing Cervantes v. Court of Appeals, 512 Phil. 210, 216 (2005) and Mayor Flores v. Sangguniang Panlalawigan ofPampanga, 492 Phil. 377, 381 (2005).

[2] Id.

[3] Cervantes v. Court of Appeals, supra note 1, at 217.

[4] Id.