Section 53. In making his appointments the mayor shall sign and file with the city clerk a certificate in the following form:
Certificate of Appointment
I appoint (name of appointee) to the position of (name of office), and I certify that in my opinion he is a recognized expert in the work which will devolve upon him, and that I make the appointment solely in the interest of the city.
or in the following form, as the case may be:
Certificate of Appointment
I appoint (name of appointee) to the position of (name of office), and I certify that in my opinion he is a person specially fitted by education, training or experience to perform the duties of said office, and that I make the appointment solely in the interest of the city.