subpoena

A subpoena (; also subpena, subpœna) or witness summons is a writ issued by a government agency, most often a court, to compel testimony by a witness or production of evidence under a penalty for failure. There are two common types of subpoenas: subpoena ad testificandum orders a person to testify before the ordering authority or face punishment. subpoena duces tecum orders a person or organization to bring physical evidence before the ordering authority or face punishment. This is often used for requests to mail copies of documents to a requesting party or directly to a court.

==Etymology== thumb|200px|right|Example of subpoena in the case Anderson v. Cryovac The term subpoena is from the Middle English suppena and the Latin phrase sub poena meaning "under penalty". It is also spelled "subpena". The subpoena has its source in English common law and it is now used almost with universal application throughout the English common law world. John Waltham, Bishop of Salisbury, is said to have created the writ of subpoena during the reign of Richard II. However, for civil proceedings in England and Wales, it is now described as a witness summons, as part of reforms to replace Latin terms with Plain English understandable to the layman.