(a) Every subpoena shall command the person to whom it is directed to appear at a specified time and place to give testimony or to produce books, papers, documents, or any other evidence, which shall be described with such particularity as necessary to identify what is desired.

(b) The investigating officer may issue subpoenas for the attendance of witnesses or for the production of books, papers, documents, or any other relevant evidence needed by the investigating officer or by the respondent.

(c) After charges have been served upon the respondent the Administrative Law Judge may, either on the Administrative Law Judge's own motion or the motion of the investigating officer or respondent, issue subpoenas for the attendance and the giving of testimony by witnesses or for the production of books, papers, documents, or any other relevant evidence.