Subpoena ad testificandum

Court order to give testimony

A subpoena ad testificandum is a court summons to appear and give oral testimony for use at a hearing or trial. The use of a writ for purposes of compelling testimony originated in the ecclesiastical courts of Church during the High Middle Ages, especially in England. The use of the subpoena writ was gradually adopted over time by civil and criminal courts in England and the European continent.

This keyword could refer to multiple things. Here are some suggestions: