Sec. 16221b. (1) If the department has a reasonable basis to believe that a licensee has violated any of the following, the department is not required to investigate under section 16221 or 16231 and may issue a letter to the licensee notifying the licensee that he or she may be in violation of the applicable section: (a) Section 7303a(4). (b) Section 7303a(5). (c) Section 17754a. (2) A letter that is issued under this section is not considered discipline.