Texas Code of Criminal Procedure - CRIM P Art. 24.03. Subpoena and application therefor

(a) Before the clerk or his deputy shall be required or permitted to issue a subpoena in any felony case pending in any district or criminal district court of this State of which he is clerk or deputy, the defendant or his attorney or the State's attorney shall make an application in writing or by electronic means to such clerk for each witness desired.  Such application shall state the name of each witness desired, the location and vocation, if known, and that the testimony of said witness is material to the State or to the defense.  The application must be filed with the clerk and placed with the papers in the cause or, if the application is filed electronically, placed with any other electronic information linked to the number of the cause.  The application must also be made available to both the State and the defendant.  Except as provided by Subsection (b), as far as is practical such clerk shall include in one subpoena the names of all witnesses for the State and for defendant, and such process shall show that the witnesses are summoned for the State or for the defendant.  When a witness has been served with a subpoena, attached or placed under bail at the instance of either party in a particular case, such execution of process shall inure to the benefit of the opposite party in such case in the event such opposite party desires to use such witness on the trial of the case, provided that when a witness has once been served with a subpoena, no further subpoena shall be issued for said witness.

(b) If the defendant is a member of a combination as defined by Section 71.01, Penal Code, the clerk shall issue for each witness a subpoena that does not include a list of the names of all other witnesses for the State or the defendant.