Extraordinary writ is a writ issued by a court exercising unusual or discretionary power. It can also be a judicial order generally issued by an appellate court to make available the remedies not regularly within the powers of lower courts. Extraordinary writs are also termed as prerogative writs. Examples of extraordinary writs are certiorari, habeas corpus, mandamus, and prohibition.
Most State have specific rules regarding how a petition for extraordinary writ is to be filed.
The following is an example of a State Statute on Petition for extraordinary writ:
Mo. App. E.D. Spec. R. 410 Petitions for Extraordinary Writs
(a) An original and five copies of all filings associated with a writ proceeding; including the petition, writ summary, suggestions in support, exhibits, suggestions in opposition, and answer, shall be filed. If a party presenting a writ petition for filing binds or clips the filings together, that party shall assemble the required documents by placing the writ summary on top, followed by the petition, suggestions in support, and any exhibits. The number of copies of briefs filed in a writ proceeding shall be governed by Rule 330(d).
(b) A party, other than a person allowed to proceed as a poor person or a person in custody who is filing a pro se writ petition, who files any document listed in subsection (a) of this rule, other than exhibits, shall also file either:
I. a floppy disk containing a copy of the filing. The floppy disk shall be double sided, high density 1.44 MB, 3 1/2 inch size. An adhesive label shall be affixed to each disk legibly identifying the caption of the case, the disk number (e.g., "Disk 1 of 2"), and the word processing format (Microsoft Word). Word format shall be used if available. If Word is unavailable, the material shall be formatted in WordPerfect 5.x or higher. The filing party shall certify that the disk has been scanned for viruses and it is virus-free; or
II. a CD-ROM or an electronic mail message with an attachment containing a copy of the filing. The filing shall comply with the requirements of subsection (b) of this rule for filing a floppy disk. A filing as an attachment to an electronic mail message shall also comply in all other respects with the requirements of Tile 84.06(h).
(c) A party who files any exhibits may also file a floppy disk, CD-ROM, or electronic mail message with an attachment containing a copy of the exhibit(s). The filing shall comply with the requirements of subsection (b) of this rule.
(d) In child custody habeas corpus proceedings, petitioner or petitioner's attorney shall complete the Writ Service Information form, using the form attached to and made a part of this rule.