Although no Bahá’í work may be published without approval, it is not mandatory to print an approval notice in any publication.
(Publishing, Bahá'í, Memorandum on: Materials to be Deposited with the Bahá'í World Centre Library, Bahá'í International Archives, Universal House of Justice 1998/2000)
https://bahai-library.com/bwc_memorandum_bahai_publishing
(Publishing, Bahá'í, Memorandum on: Materials to be Deposited with the Bahá'í World Centre Library, Bahá'í International Archives, Universal House of Justice 1998/2000)
https://bahai-library.com/bwc_memorandum_bahai_publishing