How should a vice-president be addressed when presiding in the absence of the president?

In a formal meeting setting, when the vice-president is presiding in the absence of the president, they should be addressed in a manner that reflects the authority and role of the position they are temporarily fulfilling. Addressing them as "Mr. or Madame President" maintains the decorum associated with the office of the president, which they are effectively occupying during that time. This practice reinforces the respect due to the leadership role and upholds the formalities of parliamentary procedure.

Using a title like "Chairperson" can diminish the rank and does not accurately recognize them as the acting president. First names only lack the necessary formality required in a structured meeting, where titles indicate position and authority. Thus, addressing the vice-president as "Mr. or Madame President" is appropriate and aligned with parliamentary etiquette.