subpoena du·ces te·cum /-ˌdusəsˈtikəm/
Sub·poe·na n. Law A writ commanding the attendance in court, as a witness, of the person on whom it is served, under a penalty; the process by which a defendant in equity is commanded to appear and answer the plaintiff's bill. [Written also subpena.]
Subpoena ad testificandum A writ used to procure the attendance of a witness for the purpose of testifying. -- Subpoena duces tecum A writ which requires a witness to attend and bring certain documents.
subpoena duces tecum
n : a writ issued by a court at the request of one of the
parties to a suit; it requires a witness to bring to
court or to a deposition any relevant documents under the
witness's control