§ 23. Records, documents and papers of the department. All proceedings, documents, papers and records filed or deposited with the department relating to matters within its jurisdiction and powers shall be public records; except such portions thereof as are received and accepted by the commissioner, as being of a confidential nature which when so received and accepted shall not be subject to subpoena. Copies of all official documents and orders so filed or deposited, certified by the commissioner, a deputy commissioner, counsel, a division director, or an assistant director under the seal of the department to be true copies of the originals, shall be evidence in like manner as the originals.